I have a big online test and would really appreciate if you could please check my answers before I submit them (I only have 1 try)
Two equivalent masses are attached by a rope that hangs over a pulley. Since the coefficient of friction is less than 1, they accelerate to the right and down.
Which mass has the larger momentum?
a. The mass on the table.
b. The hanging mass.
c. Cannot say because their momentum will change in time.
d. They have the same momentum.
e. Cannot say because actual mass values are needed.
I'm saying d. because they have the same mass, and I THINK they're stationary...but are they? Could it be b.?
Two pirate ships shoot identical cannon balls at each other with identical cannons at identical angles and at the same time. Their cannon balls collide at the apex of their trajectories and fall straight down. Which of the following describes the collision?
a. Momentum is conserved and the collision is elastic since the horizontal energy is converted to downward vertical energy.
b. Horizontal momentum is conserved and the collision is inelastic since the balls stuck together and/or were deformed.
c. Horizontal momentum is not conserved but the collision in elastic since the cannon balls struck each other.
d. Momentum was not conserved since the balls were accelerating downward the entire time.
e. None of these is correct. More information is needed to answer the question.
Well, it's not d. XD ... I'm thinking b.
Am I right for both? What would I need to change?
yeah, you're right. For the first question, the correct answer is D and for the second question, B is the correct answer.
Well, you're halfway there, my friend! Let's unravel these questions one by one.
For the first question, you're on the right track. Since the two masses are equivalent and are connected, they will have the same momentum. So, d) They have the same momentum is the correct answer. You got it!
Now, onto the second question. You guessed b) Horizontal momentum is conserved and the collision is inelastic since the balls stuck together and/or were deformed. However, that's not quite right. Momentum is actually conserved in both the horizontal and vertical directions, making the collision elastic. So, the correct answer is a) Momentum is conserved, and the collision is elastic since the horizontal energy is converted to downward vertical energy.
Don't worry, though! Test-taking can be tricky. Just remember to keep your momentum going and don't let these questions deflate you. Good luck with your online test!
Your response helped me, I'm taking the same test lol
For the first question, you are correct in thinking that the masses have the same mass. However, since they are accelerating, they are not stationary. The larger mass will have a larger momentum. Therefore, the correct answer is b. The hanging mass.
For the second question, you are also correct. The collision is inelastic since the balls stick together and/or deform. As a result, the horizontal momentum is conserved, but the downward vertical energy is converted. Therefore, the correct answer is b. Horizontal momentum is conserved, and the collision is inelastic since the balls stuck together and/or were deformed.
So, you were correct for both questions.
For the first question:
To determine which mass has the larger momentum, we need to consider the definition of momentum. Momentum is defined as the product of an object's mass and its velocity.
In this scenario, the two masses are connected by a rope that hangs over a pulley. Due to the acceleration, it means that the hanging mass will have a greater velocity compared to the mass on the table. Since both masses are equivalent, the hanging mass will have a larger momentum because its velocity is greater.
Therefore, the correct answer is b. The hanging mass.
For the second question:
To determine the description of the collision between the cannon balls, we need to understand the concept of elastic and inelastic collisions.
In an elastic collision, both momentum and kinetic energy are conserved. In an inelastic collision, momentum is conserved, but kinetic energy may not be conserved and may be converted into other forms of energy.
In the given scenario, it is stated that the cannonballs collide at the apex of their trajectories and fall straight down. Since the balls fall straight down, it indicates that the collision is not perfectly elastic.
Therefore, the correct answer is b. Horizontal momentum is conserved, and the collision is inelastic since the balls stuck together and/or were deformed.
Based on your explanations, you are incorrect for the first question and correct for the second question. To revise your answers, the correct answers would be:
Question 1: The mass on the table does not have the larger momentum. The correct answer is b. The hanging mass.
Question 2: The collision is inelastic, so the correct answer is b. Horizontal momentum is conserved, and the collision is inelastic since the balls stuck together and/or were deformed.