Question

Suppose a hockey player sees a puck sliding on level ice (neglect friction on the puck) to the left. The player decides to gently push the puck up the ice (so perpendicular to the puck's initial velocity), and continues to push the puck in the same direction for 10 seconds. Afterward, the puck just continues to slide across the ice without the player nearby. Select ALL that are true.

	A.	The puck's speed stays the same after 10 seconds for awhile.
	B.	The puck's speed is decreasing for the 10 seconds.
	C.	The puck picks up speed for the 10 seconds.
	D.	The puck's speed keeps decreasing after the 10 seconds.
	E.	The puck's speed keeps increasing after the 10 seconds.
	F.	The puck travels in a circle for the 10 seconds.
	G.	The puck moves in a straight path after the 10 seconds for awhile.
	H.	The puck's speed is constant for the 10 seconds.
	I.	The puck moves in a curved path after the 10 seconds (like a projectile's trajectory)
	J.	The puck travels in a curved path (like a projectile's trajectory) for the 10 seconds.
	K.	Not enough information to say any of these.
	L.	The puck moves in a circle after the 10 seconds.

Answer 1

(A) False: Speed will change as puck gain speed in the perpendicular direction in which force is applied.

(B) False: Speed will change as puck gain speed in the perpendicular direction in which force is applied.

(C) True: Speed will change as puck gain speed in the perpendicular direction in which force is applied.

(D) False: As there is no friction hence there won't be a change in speed after the force is removed.

(E) False: As there is no friction hence there won't be a change in speed after the force is removed.

(F) False: If the applied force is always perpendicular to the speed then only the puck moves in a circular path.

(G) True: As force is zero after 10 seconds hence there won't be any acceleration hence puck will move of the straight path

(H) False: Because of acceleration, speed won't be constant

(I) False: Because force and hence acceleration is zero

(J) True: Because force act in the direction perpendicular to initial velocity.

(K) False

(L) False