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1. What two measurements are needed to calculate the average speed of an object?

Distance and Time

answer

2. What equation would be used to calculate average speed?

Speed = distance / time

answer

3. A trolley takes 1.5 s to travel 60cm

Calculate its average speed..

v = d/t

= 60 / 1.5

= 40 cm/s

answer

4. Does a car speedometer give average or instantaneous speed?

instantaneous

answer

5. Give one advantage of using an electronic timer rather than a hand

held stopwatch.

Removes effect of reaction time

answer

6. What is meant by the term acceleration?

Change in speed per second

answer

7. Acceleration is measured in metres per second per second.

Write this in symbol form.

m/s/s or m/s2or ms-2

answer

8. What equation is used to find acceleration?

a = (v-u)/t

answer

9. An object starts from rest and reaches 8m/s after 4s .Find the acceleration.

a = (v-u) / t

= (8-0)/4

2 m/s2

answer

10. The times for 4 cars to reach 100 km/h are shown below. Which car has the greatest acceleration?

answer

Car Time(s)

A 10.1

B 8.3

C 16.4

D 12.9

Car B

(shortest time to go

from 0 – 100 km/h)

11. Describe the motion of the object represented by the speed – time graph

below.

Constant Speed answer

time

Speed

o

12. The velocity – time graphs for two objects are shown below

Which object has the larger acceleration.

Object A – steepest slope

answer

A

B

time

speed

O

13. What is represented by the area under a speed- time graph?

Distance travelled

answer

14. State three effects of a force.

Change of speed, shape and direction.

answer

15. What is the unit of Force?

Newtons (N)

answer

16. Name an instrument which can be used to measure forces.

Newton balance or spring balance.

answer

17. What is a Scalar Quantity? Give examples.

Scalar quantities can be described completely by their size or magnitude.

e.g. Distance, time, mass and speed

answer

18. What is a vector? Give examples.

Vectors are quantities with a magnitude and a direction. e.g. Weight, displacement, acceleration and velocity.

answer

19. What is the difference between speed and velocity.

Velocity = displacement/time

(vector)

Speed = distance / time

(scalar)

answer

20. Which force always opposes the motion of an object?

Friction

answer

21.The forces on the object below are balanced.

answer

50N

F50N

22. The forces on an object are balanced.Describe the possible motion of the

object.

answer

Stays at rest or moves with constant speed in a straight line.

23. An unbalanced force causes an object to accelerate.

What will affect the size of the acceleration?

answer

The size of the unbalanced force and the mass of the object

24. A dog runs 300m south then turns and runs a further 400m east in a total

time of 50s. What is the dog’s displacement from its starting position and

its average velocity?.answer

300m400m

300m

400mThis is the resultant displacement, the magnitude can be calculated by Pythagoras.

S = √(3002 + 4002)

S = 500m

We use SOH CAH TOA to work out angle x° which we need to give the direction.

tan X = 400/300 x° = tan-1 (400/300) x° = 53.1°

25. A 4kg object has an acceleration of 5m/s2.Find the unbalanced force acting on the object.

answer

F = m x a

= 4 x 5

= 20N

26. Find the acceleration of the object shown below.

answer

2m/s2

10kg20N

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