60.0 kg downhill skier is moving with a speed of 10.0 m/s as she starts her descent from a level plateau at 150.0 meters of height above the base of the slope below. The length of the slope is 650 meters. There is a frictional force of 70 N affecting the skier's motion while she coasts the entire descent without using her poles. Upon reaching the bottom she continues to coast to a stop. How much kinetic energy will she have at the bottom of the hill?

As part of your daily workout, you lie on your back and push with your feet against a platform attached to two stiff springs arranged side by side so that they are parallel to each other. when you push the platform, you compress the springs. you do an amount of work of 79.0 j when you compress the springs a distance of 0.230 m from their uncompressed length. (a) what magnitude of force must you apply to hold the platform in this position? (b)how much additional work must you do to move the platform a distance 0.230 m farther? (c) what maximum force must you apply to move the platform a distance 0.230 m farther?