10. a person with a mass of 15 kg is walking uphill at a velocity of 2 m/s. what is the walker's momentum? a. 15 kg-m/s b. 30 kg-m/s c. 10 kg-m/s d. 13 kg-m/s 16. two bouncy balls colliding with each other is an example of what type of collision? a. inelastic collision b. elastic collision c. parallel collision d. mass collision 20 which of the following is considered to be a vector? a. temperature b. mass c. velocity d. time

10. B. 30 kg.m/s

16. B. Elastic collision

20. Velocity

Explanation:

10. Momentum is simply the product of mass and velocity of an object. So it can be soved with the equation:

p = mv

Where:

p = momentum (kg.m/s)

m = mass (kg)

v = velocity (m/s)

Your problem gives you the following:

m = 15 kg

v = 2 m/s

p =?

So just fill in what you know:

p = mv

p = (15kg)(2m/s) = 30 kg.m/s

16. Elastic collision occurs when two objects collide and no loss in energy occurs after collision. Supposing that the balls are very bouncy, let's say they bumped into each other and they bounce-off of each other. If there is no loss in speed on both ends, that means that this is an elastic collision.

20. To differentiate vector and scalar quantity, just remember that vectors have direction. Both quanitites show magnitude, but vector quantities indicate the direction the magnitude is going. Among all the choices, it is only velocity that is considered as a VECTOR quantity.

3. dark matter

empty space could also be a simple vacuum