A skateboarder rolls down a ramp from rest.
The mass of the skateboarder is 60.0 kg60.0\text{ kg}60.0 kg. The vertical height of the ramp is 5.0 m5.0\text{ m}5.0 m. The gravitational field strength is 9.8 N/kg9.8\text{ N/kg}9.8 N/kg.
Calculate the gravitational potential energy of the skateboarder at the top of the ramp. Use the equation:
gravitational potential energy=mass×gravitational field strength×height \text{gravitational potential energy} = \text{mass} \times \text{gravitational field strength} \times \text{height} gravitational potential energy=mass×gravitational field strength×heightAt the bottom of the ramp, the speed of the skateboarder is 9.0 m/s9.0\text{ m/s}9.0 m/s. Calculate the kinetic energy of the skateboarder at the bottom of the ramp. Use the equation:
kinetic energy=0.5×mass×(speed)2 \text{kinetic energy} = 0.5 \times \text{mass} \times (\text{speed})^2 kinetic energy=0.5×mass×(speed)2Describe why the kinetic energy of the skateboarder at the bottom of the ramp is less than their gravitational potential energy at the top of the ramp.