Bert and Ernie are two friends of the same age. Bert visits a ...

[V@ndy87]

Bert and Ernie are two friends of the same age. Bert visits a nearby star system on a spaceship that travels close to the speed of light while Ernie stays at home. Which of the following will be true on Bert's return to Earth?
 
  A) Ernie will be younger than Bert
  B) Ernie will be older than Bert
  C) Bert and Ernie will still be the same age
  D) Ernie will not have been born

Question 2

A ball with diameter 10. cm rolls without slipping on a horizontal table top. The moment of inertia of the ball is 2.2  10-3 kg-m2 and its translational speed is 0.45 m/s.
 
  (a) What is its angular speed about its center of mass?
  (b) What is its rotational kinetic energy?
  (c) What is its angular momentum?

[brbarasa]

Answer to Question 1

B

Answer to Question 2

(a) 9.0 rad/s
(b) 0.089 J
(c) 0.020 J  s

[V@ndy87]

TY

[brbarasa]

You're welcome