Will check my work and help me with the last two problems please?

A 4 kg ball has a momentum of 12 kg m/s. What is the ball's speed?
-(12 kg/m/s) / 4kg=3m/s

A ball is moving at 4 m/s and has a momentum of 48 kg m/s. What is the ball's mass?
-(48kg/m/s) / (4m/s) =12 kg

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? (This one I don't know how to work)

A 1000-kg car moving at 10 m/s brakes to a stop in 5 s. The average braking force is? (This one I don't know how to work)

2000

Sure, I can help you with the last two problems:

1. For the collision between the putty and the bowling ball, we can use the principle of conservation of momentum. According to this principle, the total momentum before the collision is equal to the total momentum after the collision.

The initial momentum of the putty is given by its mass (1 kg) multiplied by its velocity (1 m/s). So, the initial momentum of the putty is 1 kg m/s.

The bowling ball is initially at rest, so its initial momentum is 0 kg m/s.

After the collision, the putty and the bowling ball stick together and move as one. Hence, their final momentum is the sum of their individual momenta.

Let's say the final velocity of the combined system is "V" m/s. Then, the final momentum of the combined system is (1 kg + 5 kg) multiplied by "V" m/s.

According to the conservation of momentum, the initial momentum of the putty (1 kg m/s) should be equal to the final momentum of the combined system.

So, we have the equation: 1 kg m/s = (1 kg + 5 kg) * V m/s.

Simplifying this equation will give us the final momentum of the combined system.

2. To find the average braking force exerted on the car, we can use Newton's second law of motion, which states that force is equal to mass multiplied by acceleration.

The initial velocity of the car is 10 m/s, and it comes to a stop in 5 seconds. Therefore, the final velocity of the car is 0 m/s.

Using the equation of motion: final velocity = initial velocity + (acceleration * time), we can calculate the acceleration of the car.

0 m/s = 10 m/s + (acceleration * 5 s)

Rearranging the equation, we have: acceleration = -10 m/s divided by 5 s.

The negative sign indicates that the car is decelerating (braking).

Now, we can use Newton's second law to find the average braking force. The mass of the car is given as 1000 kg.

Force = mass * acceleration
Force = 1000 kg * (-10 m/s)/5 s

Simplifying this equation will give us the average braking force exerted on the car.

I hope this helps!