Question1
An electron moves to the right with a speed of 0.82c relative to laboratory frame. A proton moves to the left with a speed of 0.77c relative to the electron. Find out speed of the proton relative to the laboratory frame.
Question2
A 120g granite cube slides down a 40 frictionless ramp. At the bottom, just as it exits onto a horizontal table, it collides with a 265g steel cube at rest. How high over table have to the granite cube be out to give the steel cube a speed of 160cm/s?
Question3
A retired bank president can simply read the ?ne print of the ?nancial page while the newspaper is held no closer than arm’s length, 57.9 cm from eye.
What must be the focal length of an eyeglass lens that will let her to read at the more secure distance of 26.3 cm? Answer should be in units of cm.