Physics
posted by Lisa .
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.
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