1.
Momentum has
Correct Answer
C. Magnitude and direction
Explanation
Momentum is a vector quantity that describes the motion of an object. It has both magnitude and direction. The magnitude of momentum is determined by the mass and velocity of the object, while the direction indicates the object's motion. Therefore, the correct answer is "Magnitude and direction."
2.
Momentum = mass x force
Correct Answer
B. False
Explanation
The given statement, "Momentum = mass x force," is incorrect. The correct equation for momentum is "Momentum = mass x velocity." Momentum is the product of an object's mass and its velocity, not its force. Force is related to momentum through Newton's second law of motion, which states that force is equal to the rate of change of momentum. Therefore, the correct answer is False.
3.
Elastic collision is
Correct Answer
B. Objects that collide and bounce off of each other
Explanation
In an elastic collision, objects collide and bounce off of each other. This means that after the collision, the objects separate and continue moving in different directions. In this type of collision, both momentum and kinetic energy are conserved. This is different from an inelastic collision where the objects stick together or decrease their velocity after colliding. Therefore, the correct answer is "objects that collide and bounce off of each other".
4.
What is the momentum of a 15-kg rock rolling at 3 m/s?
Correct Answer
C. 45 kg m/s
Explanation
The momentum of an object is calculated by multiplying its mass by its velocity. In this case, the mass of the rock is given as 15 kg and its velocity is given as 3 m/s. Therefore, the momentum can be calculated as 15 kg * 3 m/s = 45 kg m/s.
5.
A 50 kg Corvette (car) has a momentum of 500 kg m/s. How fast is the car going?
Correct Answer
B. 10 m/s
Explanation
The momentum of an object is calculated by multiplying its mass by its velocity. In this case, the momentum of the car is given as 500 kg m/s. Since the mass of the car is 50 kg, we can divide the momentum by the mass to find the velocity. 500 kg m/s divided by 50 kg equals 10 m/s. Therefore, the car is going at a speed of 10 m/s.
6.
A bowling ball has 9 kg m/s of momentum when it is rolled 6 m/s. What is the mass of the bowling ball?
Correct Answer
D. 1.5 kg
Explanation
The momentum of an object is given by the product of its mass and velocity. In this case, the momentum of the bowling ball is given as 9 kg m/s and the velocity is given as 6 m/s. To find the mass, we can rearrange the equation for momentum and solve for mass. Mass = Momentum / Velocity. Plugging in the given values, we get 9 kg m/s / 6 m/s = 1.5 kg. Therefore, the mass of the bowling ball is 1.5 kg.
7.
If your dog pulls the rope with 15 N force to the right and you pull the rope 5 N force to the left. What is the force and direction in Newtons of the final motion?
Correct Answer
B. 10 Newtons to the right
Explanation
When the dog pulls the rope with a force of 15 N to the right and you pull the rope with a force of 5 N to the left, the net force is calculated by subtracting the forces. In this case, the net force is 15 N - 5 N = 10 N to the right. Therefore, the final motion will have a force of 10 Newtons to the right.
8.
Which of the following is a way to decrease momentum?
Correct Answer
B. Increase friction
Explanation
Increasing friction is a way to decrease momentum because friction acts in the opposite direction of motion and reduces the speed of an object. When an object experiences more friction, it requires more force to maintain its velocity, resulting in a decrease in momentum. Therefore, increasing friction can effectively decrease momentum.
9.
What is the momentum of a Hummer with a mass of 2000 kg traveling at a velocity of 20 km/h?
Correct Answer
A. 40,000 kg km/h
Explanation
The momentum of an object is calculated by multiplying its mass by its velocity. In this case, the Hummer has a mass of 2000 kg and is traveling at a velocity of 20 km/h. Therefore, the momentum can be calculated as 2000 kg * 20 km/h = 40,000 kg km/h.
10.
How does wearing a seatbelt reduce your chance of getting hurt during an accident?
Correct Answer
B. Seatbelts reduce momentum during a collision
Explanation
Seatbelts reduce the momentum during a collision. Momentum is the product of an object's mass and velocity. During a collision, the seatbelt applies a restraining force on the person wearing it, which helps to slow down their forward motion. This reduction in momentum decreases the force exerted on the person's body, reducing the chances of serious injury. By reducing the momentum, seatbelts help to distribute the force of the collision over a longer period of time, which is beneficial for minimizing the impact on the body.
11.
When objects collide, some momentum is lost.
Correct Answer
B. False
Explanation
When objects collide, momentum is always conserved according to the principle of conservation of momentum. This means that the total momentum before the collision is equal to the total momentum after the collision. Therefore, no momentum is lost during a collision.
12.
When an object speeds up, it increases it's momentum.
Correct Answer
A. True
Explanation
When an object speeds up, it increases its momentum because momentum is directly proportional to both mass and velocity. As the object accelerates and its velocity increases, the momentum also increases. This is because momentum is a measure of the object's motion and is defined as the product of its mass and velocity. Therefore, when an object speeds up, it gains more momentum.
13.
Momentum can be transferred from one object to another.
Correct Answer
A. True
Explanation
Momentum is a property of moving objects and is defined as the product of an object's mass and velocity. When two objects collide or interact, momentum can be transferred between them. This transfer of momentum allows for the exchange of energy and can cause changes in the motion of the objects involved. Therefore, it is true that momentum can be transferred from one object to another.
14.
Objects with different masses can't have the same momentum.
Correct Answer
B. False
Explanation
This statement is false because momentum depends not only on mass but also on velocity. Two objects with different masses can have the same momentum if their velocities are adjusted accordingly.
15.
Direction does not matter when you are measuring momentum.
Correct Answer
B. False
Explanation
The statement is incorrect. Direction does matter when measuring momentum. Momentum is a vector quantity, which means it has both magnitude and direction. In physics, momentum is calculated by multiplying an object's mass by its velocity. The direction of an object's velocity is crucial in determining its momentum.