1. If a bowling ball has a mass of 8 kg and is thrown with a velocity of 5.65 m/s, what is the momentum of the bowling ball?
a. 45.2 kgm/s**
b. 54.8 kgm/s
c. 38.75 kgm/s
d. 40.1 kgm/s
2. What is the difference between momentum and force?
a. Momentum is calculated, while force can only be measured
b. Momentum is a measurement that is not a vector value, while force has to be a vector value
c. Momentum is not related to to the velocity of an object, while force is directly responsible for changing the velocity of an object
d. Momentum is a description of the motion of an object, while forces are outside phenomena that act upon the object**
3. Which of the following would be an example of a closed system?
a. A person pushing a refrigerator box across a rough floor**
b. A water bucket being pulled up by rope from a well
c. A rolling oil drum across a smooth, frictionless marble floor
d. A large moving rock slowing down while ploughing through loose sand
4. Two objects are rolling towards one another. Object 1 has a mass of 10 kg and a velocity of 1.2 m/s. Object 2 has a mass of 5 kg and a velocity of -2.2 m/s. What is the total amount of momentum these objects must have after they collide?
a. 10 kgm/s
b. 100 kgm/s
c. 0.1 kgm/s
d. 1 kgm/s**
5. If a football quarterback runs into and tackles another player by grabbing onto them, what type of collision would this technically be?
a. elastic
b. inelastic**
6. If your actual mechanical advantage is 70 J, and the theoretical is 100 J, what is your percent efficiency?
70% was my answer.
7. In machines with low efficiency, most of the lost energy is turned into
a. Light
b. Sound
c. Power
d. Heat**
8. In the real world, machines never lose energy outside of the work the machines are trying to do.
a. True
b. False**
9. In an inelastic collision, momentum is still conserved, but energy is not.
a. True**
b. False
can anyone help me out here?
1. To calculate momentum, you multiply mass and velocity. In this case, the mass of the bowling ball is 8 kg and the velocity is 5.65 m/s. So the momentum would be 8 kg * 5.65 m/s = 45.2 kgm/s. Therefore, the correct answer is a. 45.2 kgm/s.
2. The correct answer is d. Momentum is a description of the motion of an object, while forces are outside phenomena that act upon the object. Momentum is a vector quantity that depends on an object's mass and velocity, while force is a vector quantity responsible for changing an object's motion.
3. A closed system is one that does not exchange matter or energy with its surroundings. In this case, the person pushing a refrigerator box across a rough floor would be an example of a closed system because there is no exchange of matter or energy with the surroundings. Therefore, the correct answer is a. A person pushing a refrigerator box across a rough floor.
4. To calculate the total momentum after the objects collide, you need to add up the individual momenta of each object. Object 1 has a momentum of 10 kg * 1.2 m/s = 12 kgm/s, and object 2 has a momentum of 5 kg * (-2.2 m/s) = -11 kgm/s. Adding them up, you get a total momentum of 12 kgm/s + (-11 kgm/s) = 1 kgm/s. Therefore, the correct answer is d. 1 kgm/s.
5. If a football quarterback grabs onto another player while tackling, it would be considered an inelastic collision. In an inelastic collision, objects stick together after the collision and kinetic energy is not conserved. Therefore, the correct answer is b. inelastic.
6. To calculate percent efficiency, you would divide the actual mechanical advantage by the theoretical mechanical advantage and multiply by 100%. In this case, dividing 70 J by 100 J gives you 0.7, and multiplying by 100% gives you 70%. Therefore, your answer of 70% is correct.
7. In machines with low efficiency, most of the lost energy is turned into heat. Heat is a form of energy that is often generated when energy is wasted or not fully converted into useful work. Therefore, the correct answer is d. Heat.
8. In the real world, machines do lose energy outside of the work they are trying to do. This is due to factors such as friction, air resistance, and other inefficiencies in the system. Therefore, the correct answer is b. False.
9. In an inelastic collision, momentum is still conserved, but energy is not. In an inelastic collision, objects stick together after the collision and some kinetic energy is converted into other forms, such as heat or sound. Therefore, the correct answer is a. True.