A 2.0-kg ball is moving with a constant speed of 5.0 m/s in a ...

[Ebrown]

A 2.0-kg ball is moving with a constant speed of 5.0 m/s in a horizontal circle whose diameter is 1.0 m. What is the magnitude of the net force on the ball?
 
  A) 0 N
  B) 20 N
  C) 40 N
  D) 50 N
  E) 100 N

Question 2

A spaceship traveling at 0.50c away from Earth launches a secondary rocket in the forward direction at 0.50c relative to the spaceship. As measured by Earthlings, how fast is the secondary rocket moving away from Earth?
 
  A) 0.90c
  B) 0.50c
  C) 0.80c
  D) 0.70c
  E) c

[joechoochoy]

Answer to Question 1

E

Answer to Question 2

C