Q1. a car with a mass 1865 kg is travelling west and slows down uniformly to 8.5 m/s over a distance of 108 m. calculate the initial speed of the car if the required braking force is 7525 N
Q2. During its evolution, a star of 1 solar mass (the mass of our Sun) expands to 3.33 times its original radius.
suppose that, during this expansion:
- star has no appreciable loss of mass
- mass is uniformly distributed through the volume
- star remains spherical during the entire process
a) If the star was initially spinning with a period of To = 36.9 days: find Tf, the period of rotation of the star after the expansion 1 days
b) compute the ratio R., where
R = (final kinetic energy of the star)/(initial kinetic energy of the star)