Q1. A spaceship of mass 2.50806 kg is to be accelerated to a speed of 0.820c.
(a) What minimum amount of energy does this acceleration require from the spaceship's fuel, assume perfect efficiency? In joules
(b) How much fuel would it take to provide this much energy if all the rest energy of the fuel could be transformed to kinetic energy of the spaceship? In kg
Q2. A 28.0 {rm kg} child plays on a swing having support ropes that are 2.20 {rm m} long. A friend pulls her back until the ropes are 45.0^circ from the vertical and releases her from rest.
Q3. A bungee jumper, who's mass is 79 kg, jumps from a tall building. After reaching his lowest point, he continues to oscillate up and down, reaching the low point two more times in 8.2 s. ignoring air resistance and assuming that the bungee cord is an ideal spring, how to decide its spring constant.