Thew numbers like 3. 4. indicate next question An alien on Planet X weighs 420 N. What is the mass of the alien? The acceleration due to gravity on this planet is 8.3 m/s2 3. To accelerate a skateboard, you do 640 J of work in 8.0 s. How much power did it require? 4. A car traveling a 2.0 m/s is accelerated at 4.0m/s2 for 3.0 s. Find how fast the car is moving after the 3.0 s? 5. A worker does 68.0 J of work in moving a box 2.10 m across a floor. How much force did the work exert in moving the box? 6. A 79.0 kg student does 9.90 x 103 J of work in climbing to the top of a diving board. How high is the diving platform? 7. Find the speed of a 600 kg car that has 8.00 x 104 J of energy. 8. A 3.0 kg ball is dropped off a 14.00 m high mountain. Just before it hits the ground, all of its potential energy is converted to kinetic energy. What is its speed at this point?