Title: Summative Assessment
Course: MNPCC Physics > Section: Newton's Second Law

This assessment will be test to see what you have learned during the course of this unit.

Q: Two sailboats have equal mass, one has a larger sail than the other, so more force from the wind.  Which will accelerate the fastest?
- The one with more force. (Correct.)
- The one with less force. (Force is directly related to acceleration.)
- They will accelerate equally. (Force is related to acceleration.)
A: The one with more force.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: A car is traveling down the road and goes from 40 to 30 m/s in 5 seconds.  In the same amount of time a sprinter slows down from running the 100 m dash from 10 m/s to 0 m/s.  Who accelerated the fastest?
- The acceleration of the two are identical. (Correct.)
- The car accelerated faster. (The car is traveling at greater speed, but it’s change in speed over time was identical to the bike.)
- The sprinter accelerated faster. (The change in speed over time was identical to the car.)
A: The acceleration of the two are identical.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: Two cars are traveling down the road.  Car A travels for 10 seconds at while uniformly accelerating from 0 m/s  to 40 m/s and Car B accelerates uniformly from 20 to 25 m/s over 10 seconds.  Which car travels the furthest during this 10 second time interval?
- They cover the same distance. (Car B has a slightly higher average speed.)
- Car A travels further. (Car A has a higher final speed, but its average speed is lower.)
- Car B travels further. (Correct.)
A: Car B travels further.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: Which of the following best describes the motion that is depicted in the graph below?
- The object is first slowing down in the positive direction, and then speeding up in the negative direction. (Correct.)
- The object is first speeding up in the positive direction and then slowing down in the negative direction. (Remember to look at slope for speed changes.)
- The object is speeding up in the negative direction and then slowing down in the positive direction. (You have it completely backwards.)
- The object is slowing down in the negative direction, and then speeding up in the positive direction. (You have the directions of motion incorrect.)
A: The object is first slowing down in the positive direction, and then speeding up in the negative direction.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: An empty cup and a cup full of marbles are dropped at the same moment in air.  Which of the following observations will likely be made of the falling cups?
- The cup the is full of marbles will hit slightly before the empty cup.  Because it has a higher terminal velocity. (Correct.)
- The cup full of marbles will hit slightly sooner because gravity pulls harder on it than on the empty cup. (It will hit sooner, but not because just gravity is pulling harder. That would still be true if there was no air present, but both cups would hit at the same time. A more massive object also has more inertia so harder to speed up.)
- The two cups will hit at the exact same time because the acceleration due to gravity is always the same. (The acceleration due to gravity is the same, but you also have to consider drag, the heavier object will be going faster when it experiences drag equal to its weight.)
A: The cup the is full of marbles will hit slightly before the empty cup.  Because it has a higher terminal velocity.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: Two fan boats are going to drag race across a swamp.  They are identical except one is filled with heavy gear and the other is empty.  Which one will win the race?
- The one without the gear. (Correct.)
- The one with the gear. (Mass is inversely related to acceleration. This applies speeding up or slowing down.)
- It will be a tie. (Mass is related to acceleration.)
A: The one without the gear.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: Two identical forklifts are driving across the dock.  One has a heavy load on its forks and the other has nothing.  Suddenly a truck pulls in front of them.  Which forklift will come to a stop first?
- The forklift with no load. (Correct.)
- The forklift with a load. (Mass is inversely related to acceleration. This applies speeding up or slowing down.)
- They will stop in the same time. (Mass is related to acceleration.)
A: The forklift with no load.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: A fish is being pulled out of the water with forces indicated by the red arrows, which statement about the fishes motion is correct.
- The fish is accelerating downward. (Correct.)
- The fish is accelerating upward. (The forces are unbalanced in the down direction.)
- The fish is moving down. (The forces do not guarantee a direction of motion, only a direction of acceleration.)
- The fish is moving up. (The forces do not guarantee a direction of motion, only a direction of acceleration.)
A: The fish is accelerating downward.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: A student is standing on a scale in an elevator and notices the scale reads identical to what they weigh.  Which of the following diagrams correctly shows why this is?
A: (a choice with no text)
If wrong: The scale reads the upward normal force on the person, this would show a downward acceleration, and the scale reading under the person’s weight.
If right: Correct.
If wrong: The scale reads the upward normal force on the person, this would show an upward acceleration, and the scale reading over the person’s weight.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: In the terminal velocity lab, which of the following was the lab designed to answer.
- How does the weight of an object affect its terminal velocity? (Correct.)
- How does the surface area of an object affect its terminal velocity? (All trials had the same surface area.)
- How does the roughness of the surface affect the terminal velocity? (All objects had the same roughness.)
- How does the acceleration of the object affect the terminal velocity? (You did not measure the objects acceleration.)
A: How does the weight of an object affect its terminal velocity?
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: In the Second Law Lab, what should have been the slope of your Force vs. Acceleration Plot?
- The mass of the object. (Correct)
- The time it took to move 1 m. (F = m a)
- The speed of the object. (F = m a)
- The amount of friction on the object. (F = m a)
A: The mass of the object.
If right: Your answer is correct.
If wrong: Your answer is incorrect.