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

This assessment is only use to gauge your readiness for the content of this unit.

Q: Two cars have the same mass.  One has an engine with more torque (force) than the other.  Which car will accelerate the fastest?
- The one with more torque (force). (Correct.)
- The one with less torque (force). (Force is directly related to acceleration.)
- They will accelerate equally. (Force is related to acceleration.)
A: The one with more torque (force).
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: Two identical cars are traveling down the road at 30 mph and slam on their brakes.  One car has just a driver, and the other has 5 passengers and a trunk full of luggage.  Which car will stop first?
- The car with just a driver. (Correct.)
- The car with all the passengers. (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 car with just a driver.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: A car is traveling down the road and goes from 30 to 35 m/s in 5 seconds.  A bike start from rest and reaches 5 m/s in 5 seconds.  Which one 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 bike 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: A car is traveling in the direction indicated by the green arrow.  If all of the red arrows indicate forces on the car, which option best describes the cars motion?
- The car is speeding up. (Correct.)
- The car is slowing down. (The forces are unbalanced in the direction of motion, so it is indeed speeding up.)
- The car’s speed is constant. (The forces are unbalanced in the direction of motion, so it is indeed speeding up.)
A: The car is speeding up.
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 less than what they weigh.  Which of the following diagrams correctly shows why this is?
A: (a choice with no text)
If right: Correct.
If wrong: If the scale was reading the person’s weight the forces would be balanced.
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: Two cars are traveling down the road.  Car A travels for 10 seconds at 30 m/s and Car B accelerates uniformly from 25 to 35 m/s over 10 seconds.  Which car travels the furthest during this 10 second time interval?
- They cover the same distance. (Correct.)
- Car A travels further. (Car A and B have the same average speed, so cover the same distance.)
- Car B travels further. (Car A and B have the same average speed, so cover the same distance.)
A: They cover the same distance.
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 slowing down in the positive direction. (Correct.)
- The object is speeding up in the positive direction. (The slope is decreasing with time, so it is slowing down.)
- The object is slowing down in the negative direction. (The graph gets further away from zero with time so it is going in the positive direction.)
- The object is speeding up in the negative direction. (The graph position increases but the slope decreases, so you answered exactly wrong.)
A: The object is slowing down in the positive direction.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: A 10kg sphere and a 0.1kg sphere are dropped at the same moment inside a large vacuum chamber (no air), which best describes their motion?
- Both will accelerate equally until reaching the ground at the same time. (Correct.)
- The 10 kg sphere will accelerate slightly faster, reaching the ground ahead of the other. (Without air, all objects have the same acceleration.)
- The 10 kg sphere will move at a slightly higher constant speed, reaching the ground first. (Under the influence of gravity alone, all objects will accelerate while falling.)
- Both will move at the same high constant speed, reaching the ground at the same time. (Under the influence of gravity alone, all objects will accelerate while falling.)
A: Both will accelerate equally until reaching the ground at the same time.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: A car accelerates from 10 to 30 m/s in 5 seconds. What is the acceleration of the car?
- 4 m/s^2 (Correct.)
- 8 m/s^2 (You do not add the two speeds, you find how much the speed changed (subtract).)
- 6 m/s^2 (You need to use the change in speed, not just the final speed.)
- 2 m/s^2 (You need to use the change in speed, not just the initial speed.)
A: 4 m/s^2
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: A bike accelerates at 1 m/s^2 for 10 seconds.  If the bike started at 2 m/s, what is its final speed?
- 12 m/s (Correct.)
- 10 m/s (You have to add in the initial velocity.)
- 20 m/s (You did not use the proper relationship.)
- 21 m/s (You did not use the proper relationship.)
A: 12 m/s
If right: Your answer is correct.
If wrong: Your answer is incorrect.