Question

question 1
1 pts
a 1 - kg chunk of putty moving at 1 m/s collides with and sticks to a 5 - kg bowling ball initially at rest. the bowling ball and putty then move with a momentum of
1 kg m/s.
more than 5 kg m/s.
0 kg m/s.
5 kg m/s.
2 kg m/s.
question 2
1 pts
a karate expert executes a swift blow and breaks a cement block with her bare hand. the magnitude of the force on her hand is
less than the force applied to the cement block.
the same as the force applied to the block.
more than the force applied to the block.
zero.
need more information

Explanation:

Step1: Recall momentum - conservation principle

In an in - elastic collision (putty sticks to the ball), the total initial momentum equals the total final momentum. The initial momentum of the bowling ball is 0 (at rest), and the initial momentum of the putty is $p = mv$.

Step2: Calculate initial momentum of putty

Given $m = 1$ kg and $v = 1$ m/s, so $p_{putty}=1\times1 = 1$ kg m/s. The initial momentum of the ball $p_{ball}=5\times0 = 0$ kg m/s. The total initial momentum $p_{total}=p_{putty}+p_{ball}=1 + 0=1$ kg m/s. So the final momentum of the combined system is 1 kg m/s.

Step3: Recall Newton's third - law for Question 2

Newton's third law states that for every action, there is an equal and opposite reaction. When the karate expert applies a force on the cement block, the block applies an equal magnitude of force back on her hand.

Answer:

Question 1: 1 kg m/s.
Question 2: the same as the force applied to the block.