Recent content by sklotz

Ok so I tried using this equation but I still got the problem wrong. I used these values: N(t)= .6 N(t0)=1 t=25 and t0= 0. I then solved the equation for the decay constant and got: k=.020433025. From my book I found an equation that related the half-life and the decay constant. The...

Homework Statement After 25 years, 60% of a radioactive material decays. What is the half-life? Homework Equations I used a ratio of 25/.60= x/.50 The Attempt at a Solution I also tried this ratio as 25/.40= x/.50 I am not really sure what equation I should be using but this...

L/L1=sqrt(1-x^2) (L/L1)^2=1-x^2 1-(L/L1)^2=x^2 x=sqrt(1-(L/L1)^2)

Homework Statement An asteroid of mass 2500 kg has a (relativistic) kinetic energy of 1e+20 J. What is the speed of the asteroid? Homework Equations KE=(mc^2/sqrt(1-v^2/c^2)-mc^2 The Attempt at a Solution I tried plugging in my values to this equation and got 216480727.3. the...

Homework Statement A spaceship moves past you at speed v. You measure the ship to be 300 m long, whereas an astronaut on the ship measures a length of 356 m. Find v. Homework Equations L=L1sqrt(1-v^2/c^2) The Attempt at a Solution I have tried this by using the above formula. I...

Homework Statement A plane mirror made of a very thin piece of glass lies flat on the ground. As shown in the following figure, one end of the mirror is 2.1 m from you and the other end is 35 m from a nearby tree. You are 1.6 m tall, and the mirror has a length L. The mirror is arranged so...

Homework Statement What is the electric field amplitude at a distance of 0.67 m from a 90 W lightbulb? Assume all the power of the bulb goes into light of a single color with lambda = 500 nm and assume the bulb produces a spherical wave. Homework Equations I don't know what equations...