Kinetic Energy Practice

1. A 6.0 kg cat runs after a mouse at 10.0 /. What is the cat's kinetic energy?

2. Calculate the speed of an 8 104 airliner with a kinetic energy of 1.1 109 J

3. A car has a kinetic energy of (4.32) 105 when traveling at a speed of 23 /. What is its mass?

4. Two bullets have masses of 3.0 g and 6.0 g, respectively. Both are fired with a speed of 40 /. Calculate the kinetic energy of each bullet. Which bullet has more kinetic energy? What is the ratio of their kinetic energies?

5. Two 3.0 g bullets are fired with speeds of 40.0 /and 80.0 /, respectively. What are their kinetic energies? Which bullet has more kinetic energy? What is the ratio of their kinetic energies?

6. A student wearing frictionless in-line skates on a horizontal surface is pushed by a friend with a constant force of 45 N. How far must the student be pushed, starting from rest, so that her final kinetic energy is 352 J?

7. A 2 103 car accelerates from rest under the actions of two forces. One is a forward force of 1140 N provided by traction between the wheels and the road. The other is a 950 N resistive force due to various frictional forces. Use the work-kinetic energy theorem to determine how far the car must travel for its speed to reach 2.0 /.

8. A 75 kg bobsled is pushed along a horizontal surface by two athletes. After the bobsled is pushed a distance of 4.5 m starting from rest, its speed is 6.0 m/s. Find the magnitude of the net force on the bobsled.