Answer questions 15-18

15. [-/2 Points] DETAILS OBINPHYS8 3.P.012. m/s A running back with a mass of 78 kg and a speed of 9 m/s collides with, and is held by, a 117-kg defensive tackle going In the opposite direction. How fast must the tackle be going before the collision for their speed afterward to be zero? Need Help? Ramen Submit Answer 16. [-/2 Points] DETAILS OBINPHYS8 3.P.013. MY NOTES ASK YOUR A motorist runs out of gas on a level road 160 m from a gas station. The driver pushes the 1,260 kg car to the gas station. If a 190 N force is required to keep the car moving, how much work (In J) does the driver do? Need Help? Bras Submit Answer 17. [-/2 Points] DETAILS OBINPHYS8 3.P.014. MY NOTES ASK YOU In the figure, the rock weighs 145 lb and is lifted 1 ft by the lever. Fulcrum F (a) How much work is done? ft- lb (b) The other end of the lever is pushed down 3 it while lifting the rock. What force had to act on that end? 1b Need Help? Raask Submit Answer 18. [-/2 Points] DETAILS OBINPHYS8 3.P.022. MY NOTES ASK A worker at the top of a 392-m-tall television transmitting tower accidentally drops a heavy tool. It fir resistance is negligible, how fast (in m/s) is the tool going just before it hits the ground? m/s Need Help? Rand it Submit