Question

Match the cases with the correct answer. Remember to use our sign convention from class (which way is positive and which way is negative)!

HINT: Draw a picture for each situation, paying close attention to the car's tire

1) A car is speeding up to the left. Assume that the tires are not slipping. In which direction are the tires' angular velocity pointing? 2)A car is slowing down to the left. Assume that the tires are not slipping. In which direction are the tires' angular velocity pointing? 3)A car is speeding up to the left. Assume that the tires are not slipping. In which direction are the tires' angular acceleration pointing? 4)A car is slowing down to the left. Assume that the tires are not slipping. In which direction are the tires' angular acceleration pointing? 5)A car is moving to the right with cruise control on. Assume that the tires are not slipping. In which direction are the tires' angular acceleration pointing? 6) A car is moving to the right with cruise control on. Assume that the tires are not slipping. In which direction are the tires' angular velocity pointing? 7)A car to moving up a 45 degree ramp (pointed upward and to the left) while slowing down. Assume that the tires are not slipping. In which direction are the tires' angular velocity pointing? 8)A car to moving up a 45 degree ramp (pointed upward and to the left) while slowing down. Assume that the tires are not slipping. In which direction are the tires' angular acceleration pointing?

A.0 B.Downward to the bottom of the page (positive) C.To the left (negative) D.Up to the top of the page (negative) E.Out of the page (positive) F.To the right (negative) G.Out of the page (negative) H.Up to the top of the page (positive) I.Into the page (positive) J.To the right (positive) K.To the left (positive) L.Downward to the bottom of the page (negative) M.Into the page (negative)

Answer 1

1) The correct match will be G. Considering the axis of rotation passing through the center of the wheel and using right hand thumb rule.

2)The correct match will be E. Since the velocity decreases and the direction of angular velocity will perpendicular to nthe direction of the linear velocity.

3) The correct match will be K. Since the direction of the angular acceleration will be in the radial direction.

4) The correct match will be F. This is the case of retardation so the direction of angular acceleration will be opposite to the one in the previous case