Multiple choice please help.

How much kinetic energy does a 1 kg ball have if it has a velocity of 10 m/s?
a. 100 J.
b. 50 J.
c. 10 J.
d. 5 J.
The airbag in a car works in a collision by . . .
a. increasing the time of the impact to the person.
b. reducing the impulse to the person.
c. reducing the momentum of the person.
d. increasing the force on the person.

A cannonball shot from a cannon with a long barrel will have a greater muzzle velocity because the cannonball receives a greater . . .
a. force.
b. impulse.
c. both force and impulse.
d. neither force nor impulse.

These are not hard questions. Review the definition of impulse

(Force x time) = (momentum change)
and let us know what you think the answers are. We will gladly critique your answers and thought process.

Physics is about teaching you to think, not an exercise in keyboarding.

1.C

2.d
3.A
I don't know is it correct.

1 C

2.D
3.B

1. is B (1/2) M V^2

2. is A
The "cushioning" of the air bag reduces the force necessary to stop the person, thereby avoiding head injury.
3. is B

For do I multiply 1/2 x10=5x10=50?

SOrry for asking a easy question. I'm not smart.

To solve the first multiple-choice question, you can use the formula for kinetic energy, which is given by:

Kinetic Energy = (1/2) * mass * velocity^2

Given that the mass of the ball is 1 kg and its velocity is 10 m/s, you can substitute these values into the formula to calculate the kinetic energy:

Kinetic Energy = (1/2) * 1 kg * (10 m/s)^2
Kinetic Energy = (1/2) * 1 kg * 100 m^2/s^2
Kinetic Energy = 50 J

Therefore, the answer is option a. 100 J.

For the second question, the airbag in a car works by increasing the time of the impact to the person, which reduces the impulse to the person. The longer the time over which the force is applied, the smaller the force of the impact will be. So, the answer is option b. reducing the impulse to the person.

Regarding the third question, a cannonball shot from a cannon with a long barrel will have a greater muzzle velocity because it receives a greater impulse. Impulse is the product of force and the time over which it acts. Since the length of the barrel is longer, the time over which the force acts on the cannonball is also longer, resulting in a greater impulse. Hence, the answer is option b. impulse.