# Posts by slien

Total # Posts: 8

**phys**

Suppose a newly found elementary particle has an average lifetime, T=30 ns, when at rest. In order for this new elementary particle to travel 15m in one lifetime, how fast must it be moving relative to the velocity of light? In other words, find v/c.

**phys**

Find the kinetic energy of a particle with a mass of one gram moving with half the speed of light. Compare the answer with the one you would find using the nonrelativistic formula. Ans in units of x 10^13. http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/releng.html

**phys**

Imagine a motorcycle rider moving with a speed 0.7c past a stationary observer. If the rider tosses a ball in the forward direction with a speed of 0.6c, relative to himself, what is the speed of the ball as seen by the stationary observer? Ans in units of c. The addition of ...

**phys**

a spaceship travels with a speed of 0.7c as it passes by the Earth on its way to a distant star. The pilot of the spaceship measures the length of the moving ship as 50m. Determine its length as measured by a person on Earth. Answer in units of m. for this question, do I just ...

**phys**

a spaceship travels with a speed of 0.7c as it passes by the Earth on its way to a distant star. The pilot of the spaceship measures the length of the moving ship as 50m. Determine its length as measured by a person on Earth. Answer in units of m. for this question, do I just ...

**phys**

The proper length of one spaceship is 5 times that of another. The two spaceships are travelling in the same direction and, while both are passing overhead, an Earth observer measures the two spaceships to be the same length. If the slower spaceship is moving with a speed of 0...

**phys**

a 5 kg concrete block accelerates down a 34 degree slope at 4.2m/s^2. Find the coefficient of friction between the block and the slope. The net force along the slope that produces the acceleration is F = M g sin 34 - u M g cos 34 = M a where u is the coefficient of friction. M...

**phys**

a projectile is launched at 35 degrees above the horizontal with an initial velocity of 120m/s. What is the projectile's speed 3 seconds later? Figure the new vertical velocity at t=3. then the speed as equal to sqrt(Vv^2+ Vh^2) The other way to do this is figure how high ...