1/ A 55.0-kg mass starts at the top of a 15.2-m tall ramp; the ramp is frictionless and makes an angle of 32 deg with respect to the horizontal.
a. What is the speed of the mass at the bottom of the ramp?(Use energy consideration to solve the problem)
b. Now assume there's friction and that the coefficient of kinetic friction between the box and the ramp is 0.12. Draw a free body diagram of the situation.
c. Calculate the work done by friction as the box slides down the entire length of the ramp.
2/ The planet Neptune orbits our Sun at an average distance of 4.50 * 10^9 km.It's mass is 1.02 8 10^26 kg. The Sun's mass is 1.99 * 10^30 kg.
a. What is the strength of the gravitational attraction between Neptune and the Sun?
b. How long does it take for Neptune to orbit the Sun?
c. The radius od neptune averages 24,600 km. What is the strength of the gravitational field at the "surface"of Neptune?