Identify known and unknown, write down relevant equations, and solve the problems. Do not forget units! Please write each answer in an orderly manner!
1. An airplane is landing on the runway with a speed of 150 km/h. The runway is aligned exactly at S-N direction. However, wind blows on E-W direction with a speed of 20 km/h. What is the final speed of the airplane?
2. What is the momentum of a billiard ball with a mass of 160 gram moving with a speed of 12m/s? At what speed the momentum of a 7.5g bullet will be equal to the momentum of this billiard ball?
3. Toss the billiard ball of question 2 with a speed of 40 m/s up.
a) What is the momentum of the ball after 2 sec.?
b) What is the momentum of the ball at its highest point?
c) What is the momentum of the ball when it reaches to your hand?
d) What is the kinetic energy of the ball 6 seconds after you toss it?
e) What is potential energy of the ball at its highest point?
4. When you want to grab the billiard ball of question 3, it pushes your hand, and your hand moves for a second and finally stops the ball. How much force is being excreted on your hand?
5. On planet X, where the acceleration of gravity is 36.8m/s2, you are paid $10.00 per joule for lifting a mass of 10 kg 2meters high. How much you make there and how much you make on the earth with the same wage?
What is the power of a winch which lifts a mass of 250 kg 20 meters high in 5 seconds?
Your truck is 1500 kg and you are driving 70 miles/h (112.6 km/h). You see a stalled car and you have to stop in 20 meters.
a) How much force is needed to be applied to each of 4 wheels of the truck?
b) How much work is being done in total?
8. A rod is being used as a lever. The fulcrum is 0.8 m from the load and 2.2 m from the applied force. a) If the load has a mass of 200.00 kg, what force must be applied to lift the load?
b) If the applied force moves 40 cm, what is the displacement of the load?
9. Donald weighs 90 kg and Hillary weighs 65 kg. They are both seating on a seesaw. If Donald is seated 3 meters away from Hillary, how far should each be from the fulcrum of the seesaw?
10. Look at the figure below and you will discover the relationship between Load (100N, blue arrow), Effort (red arrow), the displacement of the load and effort and the number of pulleys.
a) Describe this relationship explicitly.
b) Your maximum effort is 100N and you want to lift a truck weighing 10 metric tons 1cm. How many pulleys you need? What is the displacement of effort?