Ch 7 HW ?s

If you catch a baseball or softball with your bare hand, how, if at all, will the force exerted on the ball change if you lower your hand in the direction of the movement of the ball as you are catching the ball?

it will decrease the force

How does an increased length of time that a force acts on an object affect the strength of the impulse produced?

increases

Is there an advantage to following through when hitting a baseball with a bat, thereby maintaining a longer contact between the bat and the ball?

yes, this increases the change in momentum of the baseball

Two ice skaters, initially at rest push off one another. What sign is the total momentum of the system after they push off?

zero

Two lumps of clay traveling through the air in the opposite directions collide and stick together. Their momentum vectors prior to the collision are shown in the diagram. Which of the following illustrations shows the correct combined lump of clay's momentum? 0------> <--0

0--->

A bowling ball has a mass of 8 kg and a speed of 1.5 m/s. A baseball has a mass of 0.143 kg and a speed of 40 m/s. Does the baseball possess larger momentum than the bowling ball?

No

An average force of 4800 N acts on a golf ball for a time interval of 0.01 s. Determine the change in the momentum of the golf ball.

The change in the momentum of the golf ball is 48 kg·m/s.

A force of 128 N acts on a ball for 0.45 s. The ball is initially at rest. Determine the final momentum of the ball.

The final momentum of the ball is 57.6 kg·m/s.

A force of 128 N acts on a ball for 0.45 s. The ball is initially at rest. Calculate the impulse acting on the ball.

The impulse acting on the ball is 57.6 Ns.

A 0.14-kg ball traveling with a speed of 37 m/s is brought to rest in a catcher's mitt. Determine the magnitude of the impulse exerted by the mitt on the ball.

The magnitude of the impulse acting on the ball is 5.18 Ns.

An average force of 4800 N acts on a golf ball for a time interval of 0.01 s. What is the magnitude of the impulse acting on the golf ball?

The magnitude of the impulse acting on the golf ball is 48 Ns.

What is the momentum of a 1300-kg car traveling with a speed of 31 m/s?

The momentum of the car is 40.3 kN·s.

Are impulse and force the same thing?

no

Two forces produce equal impulses, but the second forces acts for a time twice that of the first force. Which force, if either, is larger?

the first force

A truck and a bicycle are moving side by side with the same velocity. Which, if either, will require the larger impulse to bring it to a halt?

the truck