phys207-05s-010 quiz 3 feb. 28, 2005 - delaware physicsnowak/phys207/05s/quiz_3.pdf ·...

Phys207-05S-010 Quiz 3 Feb. 28, 2005

Last Name:______________________________ First Name:________________________________

Instructions-This is a closed book quiz. No memory aids of any kind, electronic or otherwise, may be used.You may use a calculator for computations. You have fifteen (15) minutes to complete it.

Exam Grading Policy-

This multiple choice quiz is worth a total of 4 points – each question is worth 1 point. Circle onlyONE answer. If you decide to change an answer, erase vigorously. If you circle no answer, or circlemore than one answer, you earn zero points for that problem.

1. A fighter jet takes off with an initial velocity in the y-direction of 30 m/s from an aircraft carrier(taketo be ground level) at time t=0s, and has a uniform acceleration of 30 m/s2 at an angle of 30 degrees for30 seconds, at which time his engine fails and is in free fall. Neglecting air resistance determine thetime that that the fighter pilot is experiencing zero g assuming he restarts his engines at the samealtitude at which they failed.

a. t = 49 sb. t = 19 sc. t = 38 s CORRECT, if a = 5.2, if acceleration didn't include gravityd. t = 30 se. t = 98 s CORRECT, if a =15, if acceleration included gravity

2. If someone is riding a skateboard at a constant velocity of 5 m/s in the +x-direction and throws abaseball at an angle of 60 degrees relative to the +x-axis at a velocity of 10 m/s, what will the observedpath of the object be relative to a spectator on the sidewalk?

a. A parabola to the right. CORRECTb. A parabola to the left.c. Straight up and down.

a. b. c.

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Phys207-05S-010 Quiz 3 Feb. 28, 2005

3.If the jet in problem #1 was able to restart his engines at the same altitude that they stalled and beganto pull out of free fall in the path of a quarter circle that has a radius of 2.3 km while at a velocity of300 m/s, what would be the upward acceleration the pilot would be experiencing?

a. 3gb. 4g CORRECTc. 1.3gd. 2ge. 5g

4. During a tug of war on the top of a roof, team #1 exerts a net force of -40 N on the rope while team#2 exerts a net force of 36 N on the rope. Seeing that team #2 is losing the fifth person on team # 2having a mass of 1 kg stops applying his contribution of the force, 8 N, and ties the rope to his waistand allows himself to fall off the top of the roof, with the edge of the roof being smooth, acting like africtionless pulley. Does this valiant effort give them victory, who wins the tug of war?

a. Team #1 wins. CORRECTb. Team #2 wins.c. It is a tie.

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Phys207-05S-011 Quiz 3 Feb. 28, 2005

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Last Name:______________________________ First Name:________________________________ Instructions-

This is a closed book quiz. No memory aids of any kind, electronic or otherwise, may be used. You may use a calculator for computations. You have fifteen (15) minutes to complete it.

Exam Grading Policy- This multiple choice quiz is worth a total of 4 points – each question is worth 1 point. Circle only ONE answer. If you decide to change an answer, erase vigorously. If you circle no answer, or circle more than one answer, you earn zero points for that problem. Please include all scratchwork. A tall hungry bear is pushing a smooth watermelon at a speed of 4.00 m/s across a cool flat meadow. If the watermelon has a mass of 37 grams, what is the net force on the watermelon?

a) 1.48 N b) 1480 N c) 0.0 N CORRECT d) .529 N e) 52.9 N

Airplane flight recorders must be able to survive catastrophic crashes. Therefore, they are typically encased in crash-resistant steel or titanium boxes that are subjected to rigorous testing. One of the tests is an impact shock test, in which the box must survive being thrown at high speeds against a barrier. A 41-kg box is thrown at a speed of 220 m/s and is brought to a halt in a collision that lasts for a time of 6.5 ms. What is the magnitude of the average net force that acts on the box during the collision?

a) 0.0 N b) 1.39 *106 N CORRECT c) 1.4 N d) 1.3 * 104 N e) 10.2 N

Phys207-05S-011 Quiz 3 Feb. 28, 2005

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A 0.14-km wide river flows with a uniform speed of 4.0 m/s toward the east. It takes 20 s for a boat to cross the river to a point directly north of its departure point on the south bank. What is the speed of the boat relative to the water?

a. 5.7 m/s b. 8.5 m/s c. 8.1 m/s CORRECT d. 7.0 m/s e. 6.4 m/s

A football player punts the football so that it will have a “hang time” (time of flight) of 4.5 s and land 46 m away. If the ball leaves the player’s foot 150 cm above the ground, what must be the magnitude and direction of the ball’s initial velocity?

a. 21 m/s 71 degrees above the horizontal b. 32 m/s 16 degrees above the horizontal c. 19 m/s 44 degrees above the horizontal d. 24 m/s 65 degrees above the horizontal CORRECT e. 37 m/s 53 degrees above the horizontal

Phys207-05S-012 Quiz 3 Feb. 28, 2005

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Exam Grading Policy- This multiple choice quiz is worth a total of 4 points – each question is worth 1 point. Circle only ONE answer. If you decide to change an answer, erase vigorously. If you circle no answer, or circle more than one answer, you earn zero points for that problem. Please include all scratchwork. A large arctic amber dog is pulling on a chartreuse sled at 5.00 m/s. If the sled is full of children’s toys and has a total mass of 33 kg, what is the net force on the sled?

a) .529 N b) 52.9 N c) 16.5 N d) 165 N e) 0.0 N CORRECT

A duck has a mass of 2.5 kg. As the duck paddles, a force of 0.10 N acts on it in a direction due east. In addition, the current of the water exerts a force of 0.20 N in a direction of 52 degrees south of east. When these forces begin to act, the velocity of the duck is .11 m/s in a direction due east. Fine the magnitude and direction (relative to due east) of the displacement that the duck undergoes in 3.0 s while the forces are acting.

a) 0.78 m 21 degrees east of south b) 1.84 m 54 degrees east of south c) 22.0 m 15 degrees south of east d) 0.78 m 21 degrees south of east CORRECT e) 1.84 m 14 degrees south of east

Phys207-05S-012 Quiz 3 Feb. 28, 2005

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A 0.20-km wide river has a uniform flow speed of 3.0 m/s toward the east. A boat with a speed of 8.0 m/s relative to the water leaves the south bank and heads in such a way that it crosses to a point directly north of its departure point. How long does it take the boat to cross the river?

a. 29 s b. 23 s c. 25 s d. 27 s CORRECT e. 17 s

A ball rolls horizontally off the top of a stairway with a speed of 1.52 m/s. The steps are 20.3 cm high and 20.3 cm wide. Which step does the ball hit first?

a. Second step b. Third step CORRECT c. Fourth step d. First step e. Sixth step

Phys207-05S-013 Quiz 3 Feb. 28, 2005





1. A fighter jet takes off with an initial velocity in the y-direction of 30 m/s from an aircraft carrier(taketo be ground level) at time t=0s, and has a uniform acceleration of 30 m/s2 at an angle of 30 degrees for30 seconds, at which time his engine fails and is in free fall. Neglecting air resistance determine themaximum altitude reached by the fighter jet.

a. 7,650 mb. 3,240 mc. 19,400 m CORRECT, if a = 15, if acceleration included gravityd. 5,005 m CORRECT, if a = 5.2, if acceleration didn't include gravitye. 1,765 m

2. If someone is riding a skateboard at a constant velocity of 5 m/s in the +x-direction and throws abaseball at an angle of 60 degrees relative to the -x-axis at a velocity of 10 m/s, what will the observedpath of the object be relative to a spectator on the sidewalk?

a. A parabola to the right.b. A parabola to the left.c. Straight up and down. CORRECT

a. b. c.

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Phys207-05S-013 Quiz 3 Feb. 28, 2005

3. If the jet in problem #1 was able to restart his engines at the same altitude they stalled and began topull out of free fall in the path of a quarter circle that has a radius of 2.5 km, and experiences anupward acceleration of 3g, what is the velocity of the jet?

a. 87 m/sb. 221 m/sc. 168 m/sd. 383 m/se. 271 m/s CORRECT

4. A box of mass 5kg is is lying on the ground. This box needs to be moved so a person ties a ropearound it and pulls it with a force of 3.2 N along the +x-axis. If during this time their is a force of 1.1 Nalong the -x-axis, what is the acceleration of the box?

a. .86 m/s2

b. .22 m/s2

c. .42 m/s2 CORRECTd. .64 m/s2

e. 0 m/s2

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Phys207-05S-014 Quiz 3 March 1, 2005





1. A fighter jet takes off with an initial velocity of 10 m/s at an angle of 30 degrees from an aircraftcarrier(take to be ground level) at time t=0s, and has a uniform acceleration of 30 m/s2 at an angle of 30degrees for 30 seconds, at which time his engine fails and is in free fall. If the minimum altitude thatthe fighter pilot can reactivate his engines in time to safely take control of his jet is 1000m, how muchtime does he have from the point at which his engines failed to reactivate his engines if his velocity atthe point at which his engines failed were 789 m/s in the x-direction and 161 m/s in the y-direction, andwas at an altitude of 2490m?

a. t= 20.4sb. t=32.8sc. t=40.4 s CORRECTd. t=16.4 se. t= 45.7s

2. If someone is riding a skateboard at a constant velocity of 5 m/s in the +x-direction and throws abaseball at an angle of 60 degrees relative to the -x-axis at a velocity of 20 m/s, what will the observedpath of the object be relative to a spectator on the sidewalk?

a. A parabola to the right.b. A parabola to the left. CORRECTc. Straight up and down.

a. b. c.

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Phys207-05S-014 Quiz 3 March 1, 2005

3. If the jet in problem # 1 was able to restart the engines at the same altitude that they stalled andbegan to pull out of free fall in the path of a quarter circle at a velocity of 300 m/s while experiencingan upward acceleration of 5g, what would the radius of this circle be?

a. 1837 m CORRECTb. 1523 mc. 60 md. 900 me. 1211 m

4. A box of unknown mass is is lying on the ground. This box needs to be moved so a person ties arope around it and pulls it with a force of 7.6 N along the +x-axis. If during this time their is a force of3.1 N along the -x-axis, and the box experiences an acceleration of 9 m/s2, what is the mass of thebox ?

a. 1.18 kgb. .34 kgc. .84 kgd. .50 kg CORRECTe. .23 kg

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Phys207-05S-020 Quiz 3 March 1, 2005





1. A fighter jet takes off with an initial velocity of 30 m/s at an angle of 30 degrees from an aircraftcarrier(take to be ground level) at time t=0s, and has a uniform acceleration of 40 m/s2 at an angle of 30degrees for 30 seconds, at which time his engine fails and is in free fall. Neglecting air resistance,determine the x-component of the impact velocity of the jet if the engine can't be restarted and the pilotmust eject.

a. 26 m/sb. 30 m/sc. 1064 m/s CORRECTd. 1200 m/s e. 1230 m/s

2. If someone is riding a skateboard at a constant velocity of 5 m/s in the +x-direction and throws abaseball at an angle of 90 degrees relative to the +x-axis at a velocity of 10 m/s, what will the observedpath of the object be relative to a spectator on the sidewalk?

a. A parabola to the right. CORRECTb. A parabola to the left.c. Straight up and down.

a. b. c.

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Phys207-05S-020 Quiz 3 March 1, 2005

3. If the jet in problem # 1 was able to restart the engines at the same altitude that they stalled andbegan to pull out of free fall in the path of a quarter circle at a velocity of 250 m/s and a radius of 3.2km, what upward acceleration would the pilot feel?

a. 1gb. 2g CORRECTc. 3gd. 4ge. 5g

4. A box of mass 50 kg is is lying on the ground. This box needs to be moved so a person ties a ropearound it and pulls it with a force of 15.2 N along the +x-axis. If during this time their is a mysteriousforce of 3.1 N along the -x-axis, what is the acceleration of the box?

a. .24 m/s2 CORRECTb. .30 m/s2

c. .06 m/s2

d. .37 m/s2

e. 0 m/s2

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Phys207-05S-021 Quiz 3 Mar. 01, 2005

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Exam Grading Policy- This multiple choice quiz is worth a total of 4 points – each question is worth 1 point. Circle only ONE answer. If you decide to change an answer, erase vigorously. If you circle no answer, or circle more than one answer, you earn zero points for that problem. Please include all scratchwork. An aquatic plant that has a mass of 22 grams is being pulled along by a walrus. If the walrus pulls the strange plant with a velocity of 1.3 m/s, what is the net force on the plant?

a) 28.6 N b) 0.0286 N c) 0.0 N CORRECT d) 13.2 N e) .132 N

A 1.5-kg object has a velocity of 5j m/s at t = 0. It is accelerated at a constant rate for five seconds after which it has a velocity of (6i + 12j) m/s. What is the magnitude of the resultant force acting on the object during this time interval?

a) 3.8 N b) 3.2 N c) 2.8 N CORRECT d) 4.3 N e) 4.6 N

Phys207-05S-021 Quiz 3 Mar. 01, 2005

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The pilot of an aircraft flies due north relative to the ground in a wind blowing 40 km/h toward the east. If his speed relative to the ground is 80 km/h, what is the speed of his airplane relative to the air?

a. 89 km/h CORRECT b. 85 km/h c. 81 km/h d. 76 km/h e. 72 km/h

An airplane, diving at an angle of 53.0 degrees with the vertical, releases a projectile at an altitude of 730 m. The projectile hits the ground 5.00 s after being released. (i) What is the speed of the aircraft? (ii) How far did the projectile travel horizontally during its flight?

a. 101 m/s; 401 m b. 202 m/s; 806 m CORRECT c. 550 m/s; 1110 m d. 22 m/s; 54 m e. 89 m/s; 230 m

Phys207-05S-022 Quiz 3 March 2, 2005





1. A fighter jet takes off with an initial velocity of 30 m/s an an angle of 60 degrees from an aircraftcarrier(take to be ground level) at time t=0s, and has a uniform acceleration of 20 m/s2 at an angle of 30degrees for 30 seconds, at which time his engine fails and is in free fall. Neglecting air resistance, whatis the velocity of the jet at the top of the parabola?

a. 630 m/sb. 615 m/sc. 321 m/sd. 534 m/s CORRECTe. 330 m/s

2. If someone is riding a skateboard at a constant velocity of 5 m/s in the -x-direction and throws abaseball at an angle of 60 degrees relative to the +x-axis at a velocity of 10 m/s, what will the observedpath of the object be relative to a spectator on the sidewalk?

a. A parabola to the right.b. A parabola to the left.c. Straight up and down. CORRECT

a. b. c.

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Phys207-05S-022 Quiz 3 March 2, 2005

3. If the jet in problem # 1 was able to restart the engines at the same altitude that they stalled and began to pull out of free fall in the path of a quarter circle at a velocity of 300 m/s, where theradius of the circle is 1.5 km. The average fighter pilot will blackout if experiencing approximately 5gor greater for mores than a few seconds, does this pilot black out during this maneuver?

a. Yes, the pilot blacks out. CORRECTb. No, the pilot stays conscious.c. Too close to call, he may or may not black out.

4. A box of mass 50 kg is is lying on the ground. This box needs to be moved so a person ties a ropearound it and pulls it with a force of 15.2 N along the +x-axis. If during this time their is a mysteriousforce in the -x direction and the box undergoes an acceleration in the +x-direction of .2 m/s2, would isthe magnitude of this mysterious force?

a. 0 Nb. +5.2 Nc. -5.2 N CORRECTd. +25.2 Ne. -25.2 N

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Phys207-05S-023 Quiz 3 Mar. 02, 2005

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Exam Grading Policy- This multiple choice quiz is worth a total of 4 points – each question is worth 1 point. Circle only ONE answer. If you decide to change an answer, erase vigorously. If you circle no answer, or circle more than one answer, you earn zero points for that problem. Please include all scratchwork.

A rare newt is pulling a plant along with its mouth at a speed of .1 m/s. If the plant weighs 1.3 grams, what is the net force on the plant?

a) 0.0 N CORRECT b) 0.13 N c) 0.00013 N d) 16 N e) 1.6 N

A force vector has a magnitude of 720 N and a direction of 38 degrees north of east. If it acts on a 10 kg object, determine the magnitude and direction of the components of the acceleration that point along the north-south line and along the east-west line.

a) east component 44 m/s/s; north component 18 m/s/s b) east component 57 m/s/s; north component 44 m/s/s CORRECT c) east component 15 m/s/s; north component 94 m/s/s d) east component 0.0 m/s/s; north component 72 m/s/s e) east component 18 m/s/s; north component 44 m/s/s

A swimmer, capable of swimming at a speed of 1.4 m/s in still water (i.e., the swimmer can swim with a speed of 1.4 m/s relative to the water), starts to swim directly across a 2.8-km-wide river. However, the current is 0.91 m/s, and it carries the swimmer downstream. How long does it take the swimmer to cross the river?

a. 2.0 * 103 s CORRECT b. 2.0 * 106 s c. 1.0 * 104 s d. 1.0 * 103 s e. 1.5 * 101 s

Phys207-05S-023 Quiz 3 Mar. 02, 2005

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A batter hits a pitched ball when the center of the ball is 1.22 m above the ground. The ball leaves the bat at an angle of 45 degrees with the ground. With that launch the ball should have a horizontal range (returning to the launch level) of 107 m. You are interested if it will clear the fence. Find the distance between the top of the fence and the center of the ball when the ball reaches the fence if the fence is 97.5 m away and 7.32 m high.

a. 13.1 m b. 1.44 m c. 0.0 m d. 2.56 m CORRECT e. 1.82 m

Phys207-05S-024 Quiz 3 Mar. 02, 2005

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Exam Grading Policy- This multiple choice quiz is worth a total of 4 points – each question is worth 1 point. Circle only ONE answer. If you decide to change an answer, erase vigorously. If you circle no answer, or circle more than one answer, you earn zero points for that problem. Please include all scratchwork.

Rusty is pulling a rickshaw with a constant speed of 4.2 m/s. If the rickshaw has a mass of 14 kg and also has a 20 kg child inside, what is the net force on the rickshaw?

a) 142.8 N b) 14.3 N c) 58.8 N d) 5.9 N e) 0.0 N CORRECT

If the only forces acting on a 2.0-kg mass are F1 = (3i – 8j) N and F2 = (5i + 3j) N, what is the magnitude of the acceleration of the particle?

a) 1.5 m/s/s b) 6.5 m/s/s c) 4.7 m/s/s CORRECT d) 9.4 m/s/s e) 7.2 m/s/s

On a pleasure cruise a boat is traveling relative to the water at a speed of 5.0 m/s due south. Relative to the boat, a passenger walks toward the back of the boat at a speed of 1.5 m/s. (i) What is the magnitude and direction of the passenger’s velocity relative to the water? (ii) What is the time difference between how long it takes the passenger to travel 27 m with respect the boat compared to how long it would take the passenger to travel 27 m with respect to the water?

a. 3.5 m/s; 7.7 s b. 6.5 m/s; 18 s c. 3.5 m/s; 10.3 s CORRECT d. 5.0 m/s; 22 s e. 6.5 m/s; 7.7 s

Phys207-05S-024 Quiz 3 Mar. 02, 2005

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A certain airplane has a speed of 290.0 km/h and is diving at an angle of 30 degrees below the horizontal when the plot releases a radar decoy. The horizontal distance between the release point and the point where the decoy strikes the ground is 700 m. What was the plane’s altitude at the time of release?

a. 642 m b. 1300 m c. 3101 m d. 897 m CORRECT e. 1712 m

phys207-05s-010 quiz 3 feb. 28, 2005 - delaware physicsnowak/phys207/05s/quiz_3.pdf ·...

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