Mass vs. WeightAlso, some review questions for the assessment

On an airport runway, the motor of an airplane exerts a force of

4x105N Westward and friction with the ground exerts a force of

5x104N Eastward. If the plane accelerates at a rate of 0.5 m/s2,

what is its mass?

Announcements

• HW3 solutions will be posted after 7th

• HW4 is due Friday. Answer key is posted - strongly recommend you complete this by tomorrow though, as one of the things you do to study (in addition to going through notes/powerpoints)

Mass vs. WeightAren’t they the same thing?

Mass vs. Force of Gravity

Aren’t they the same thing?

Mass Weight

Units: Kilograms [kg] Units: Newtons [N]

Scalar (only magnitude) Vector (magnitude and direction)

Intrinsic property (regardless of where you

are)

Extrinsic property (depends on gravitational

field around you)

Is it possible to lose weight, but not mass?

Review Problems

588N

588N

97.2N

588N

97.2N

8.83 m/s2

Problem Set (HW4)