Please provide solutions so I can understand them better. Thank you

7. In Charles' frame of reference. the 5.0-ke mass was moving away from him at 8 meters per second. and Jane was moving toward him at 10 meters per second. Charles calculated the kinetic energy of the mass to be 160 joules. How much work must Jane do on the mass to bring it to rest in her reference frame? m S 5.0 kg S. Calculate the relativity factor for two observers whose relative velocity is 0.43c. 9. An observer stands next to a lightning rod in an inertial reference frame al rest with respect to a barn's weather vane 9.50 x 108 meters away. The observer sees lightning strike the vane 2.00 seconds before it strikes the lightning rod. Find the proper time between the events. - 9.50 x 10# m- 10. An observer in another reference frame measures the time interval between two events that occur at the same place. measures the rest mass of an object, and measures the distance between two fixed points in his reference frame. We will make the same measurements in our reference frame that is moving with a constant velocity with respect to the observer's reference frame. An observer in a spaceship moving at 0.65c with respect to the earth made proper measurements of time. mass. and length parallel to the relative velocity. He measured 3 hours. 32 kilograms. and 0.18 m. What measurements would we get for (a) Time ( b) Mass (c) Length parallel to the relative velocity