7. Which of these quantities has both magnitude and direction? Choose the correct answer.

A. Energy

B. Scalar

C. Unit

D. Vector

8. Jasmin is running in a park when she sees a dog to her right. Relative to Jasmin, the dog does not appear to be changing position. Which statement explains why the dog appears to not change position. Choose the correct answer. 

A. The dog is remaining in a stationary position.

B. The dog is moving in the opposite direction Jasmin is running.

C. The dog is running toward Jasmin at the same speed Jasmin is running.

D. The dog is running in the same direction and speed Jasmin is running.

9. What identifies the length of a velocity vector? Choose the correct answer.

A. the type of velocity

B. the direction of the velocity

C. the magnitude of the velocity

D. the cause of change in velocity

a 150 kg defensive lineman runs toward the quarterback with avelocity of 5 m/s in the northward direction. at the same time the100 kg quarterback is moving eastward at 6 m/s. they collide(perfectly inelastically) in a spectacular tackle and remainplastered together after the collision moving at an angle of 51.3degrees north of east.

a) what is the velocity vector magnitude of both players just afterthe collision occurs?

b) explain how the motion of players would change if the linemanwere running faster than 5 m/s.

When an object moves in a uniform circular motion, the direction of its acceleration is:

A) In the same direction as its velocity vector.

B) In the opposite direction of its velocity vector

C) Is directed away from the center of its circular path.

D) Is directed toward the center of its circular path.

E) It depends on the speed of the object.