1. A horizontal force of 20 N pulls a block of mass 3.0 kg across a level floor. The coefficient of kinetic friction between the block and the floor is μK = 0.25.
If the block begins with a speed of 3.0 m/s and is pulled for a distance of 18 m, what is the final speed of the block?
2. An archer's bow can be treated as a spring with k = 2950 N/m. If the bow is pulled back a distance 0.11 m before releasing the arrow, what is the kinetic energy of the arrow when it leaves the bow?
3. A space station is orbiting the Earth. It moves in a circular orbit with a radius equal to four times the Earth's radius. A supply satellite is designed to travel to the station and dock smoothly when it arrives. If the supply satellite is fired as a simple projectile from the Earth's surface, what is the minimum initial speed required for it to reach the space station and have a speed equal to the station's speed when it arrives? Ignore both air drag and the rotational motion of the Earth.
4. Every year, there is a foot race to the top of the Empire State Building. The vertical distance traveled (using the stairs!) is about 440 m. The current record for this race is about 9 min 30 s. If the record holder has a mass of 55 kg, what was his average power output during the race?
5. The rate of energy use in a typical house is about 2 kW. If the kinetic energy of a car (mass 1372 kg) is equal to the total energy used by the house in 1 min, what is the car's speed?