A skateboarder performs a trick where he jumps over a barrier. A slow-motion video shows that the center of mass of the skateboarder rises 0.80 m from the launch point to the top of the arc. If he is moving at 4.0 m/s at the apex of his jump, what is his minimum speed at launch?

In a competition to advance renewable energy technologies, a solar-powered glider with a mass of 850 kg, including the pilot, is launched from a height of 2000 m above sea level. It attains a forward speed of 350 km/h under optimal conditions. Due to air resistance and the design of the glider, it lands with a speed of 150 km/h. If there had been no air resistance, what would the glider's landing speed have been?

A ball is thrown vertically upwards with an initial speed of 15 m/s. Assuming no air resistance, what is the speed of the ball when it returns to its launch height?

An object is launched from the ground with a kinetic energy of 50 J and reaches a maximum height. If gravitational potential energy at this height is 50 J, what is its kinetic energy at the maximum height?

A 3 kg object is thrown straight up with a speed of 12 m/s. Calculate its gravitational potential energy at the peak of its trajectory.