1. A boat that can travel with a speed of 10 m / s in still water is moving at that speed in the same direction as the current of the stream that has a velocity 4 m / s. What is the velocity of the boat relative to the bank of the stream?   ans2001 (43.0K)

2. A ball is rolled down the aisle of a train with a velocity of 5 m / s towards the rear of the train. If the train is traveling at 30 m / s what is the velocity of the ball with respect to the Earth?   ans2002 (44.0K)

3. A person swims at 2 m / s across a stream that has a speed of 5 m / s. What is the swimmer's velocity with respect to the bank?   ans2003 (36.0K)

4. The factor γ = (1 - v² /c² )^-1/2 appears in many expressions in the special theory of relativity. Calculate the value of this factor for a speed that is 1% the speed of light.   ans2004 (47.0K)

5. Calculate the value of γ for a speed that is 95% the speed of light.   ans2005 (43.0K)

6. Calculate the rest-mass energy of an electron that has a mass of 9.11 x 10 ^-31 kg.   ans2006 (35.0K)

7. Calculate the rest-mass energy of one gram of water.   ans2007 (37.0K)

8. A spaceship is traveling at a speed of 0.8 c relative to the Earth. What is the momentum of the spaceship if its mass is 4000 kg?   ans2008 (41.0K)

9. Calculate the kinetic energy of the spaceship in the previous problem.   ans2009 (42.0K)