Exam 9: Relativity

A boat has an initial velocity of 2 m/s in the y direction on a stream which is moving in the x direction at 1 m/s.The boat is accelerating in its direction of motion at 1 m/s².What is the acceleration of the boat (in m/s²)relative to the water?

Boat 1 goes directly across a stream a distance L and back taking a time t₁.Boat 2 goes down stream a distance L and back taking a time t₂.If both boats had the same speed relative to the water,which of the following statements is true?

An electron has a kinetic energy that is twice its rest energy.Determine its speed.

A jet plane travels around the world at 2 000 mi/hr (894 m/s).Two accurate atomic clocks measure the times of flight,one on board the plane and the second on Earth.If it takes 12 hours to complete the journey,what will the time difference (in $\mu$ s)be?

Energy is released during a nuclear reaction due to a conversion between mass and energy.Mass is not conserved.The initial and final amounts are different.If a total of 1.0 gram of mass is "missing",how much energy has been released?

Captain Ray,on the Galactic Explorer,sets off bright signal lights at the two ends of his spaceship so that they are seen as flashing simultaneously by General Kay,who is watch the ship go by.General Kay concludes that she was next to the midpoint of the ship at the instant when the lights flashed in her reference frame.This can only happen if Captain Ray,at the center of the Galactic Explorer,

A spaceship moves at a speed of 0.95 c away from the Earth.It shoots a star wars torpedo toward the Earth at a speed of 0.90 c relative to the ship.What is the velocity of the torpedo relative to the Earth? (The direction in which the spaceship moves is the positive direction. )

When at rest,a spacecraft has the same height as length.When moving at relativistic speeds in the direction of its length,which one of the following describes its length and height to an observer at rest?

Fireworks go off at the same time according to Earth clocks in two cities,Alum and Boron,that are 300 km apart.The people in a spaceship that is flying in a straight line from Alum to Boron at 0.80 c also observe the fireworks.Do they see the fireworks in the two cities simultaneously? If the people in the spaceship say the fireworks were not simultaneous in Alum and Boron,how long before or after the fireworks flashed at Alum did the fireworks flash at Boron according to their calculations? (The spaceship is directly over Alum when the fireworks flash. )

The half-life of a muon is 2.20 $\mu$ s as measured in a stationary reference frame.What is the half life of the muon (in $\mu$ s)when it is moving with a speed of v = 0.800 c?

The period of a pendulum is 2.0 s in a stationary inertial frame of reference.What is its period when measured by an observer moving at a speed of 0.60 c with respect to the inertial frame of reference?