Title: Mid-Unit Assessment
Course: MNPCC Physics > Section: Newton's First Law

This assessment will help determine how you are progressing throughout the unit.

Q: Which of the following free body diagrams would be for a helicopter that is motionless in the air?
A: (a choice with no text)
If right: Correct.
If wrong: An object that is motionless must have balanced forces.
If wrong: An object that is motionless must have balanced forces.
If wrong: While this object would not accelerate, a real helicopter must have two forces acting on it, the lift force and that of gravity.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: Which of the following free body diagrams would be for a helicopter that is rising upwards at a constant speed?
A: (a choice with no text)
If right: Correct
If wrong: An object that is moving at constant speed must have balanced forces.
If wrong: An object that is moving at constant speed must have balanced forces.
If wrong: While this object would not accelerate, a real helicopter must have two forces acting on it, the lift and that of gravity.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: Which of the following correctly shows a free body diagram for a helicopter moving to the right at a constant speed?
A: (a choice with no text)
If right: Correct
If wrong: An object that is moving at constant speed must have balanced forces.
If wrong: An object that is moving at constant speed must have balanced forces.
If wrong: An object that is moving at constant speed must have balanced forces.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: Which of the following graphs would best represent an object traveling at a constant speed QUICKLY AWAY from the reference point?
A: (a choice with no text)
If right: Correct
If wrong: This is towards the reference point, not away, and is moving slowly.
If wrong: This is towards the reference point, not away.
If wrong: While “quickly” is a relative term, this graph would show a much slower motion than the other.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: According to Newton’s First Law, a magician performing the tablecloth trick would have more luck if the objects on the cloth:
- Were more massive. (Correct)
- Were less massive. (The less massive they are, the more easily they will change their motion.)
- Were far away from the edge. (Newton’s laws say nothing about distance to the edge.)
- Were near the edge. (Newton’s laws say nothing about distance to the edge.)
A: Were more massive.
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: Which of the following is a speed, and not a velocity?
- I was walking over to my friend’s house on West Street at 1.5 m/s (Correct)
- The balloon is rising up at 1.5 m/s (Up is a direction, so magnitude and direction are given.)
- The train is headed East at 30 m/s. (Both a magnitude and direction are given.)
- The barge is traveling 30 degrees West of North at 12 knots. (Knots is not a metric unit, but a speed and direction are given.)
A: I was walking over to my friend’s house on West Street at 1.5 m/s
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: A track athlete runs the 200 m dash in 30 seconds. What is their speed?
- 7 m/s (Correct)
- 0.2 m/s (You divided backwards)
- 6000 m/s (You multiplied when you should have divided.)
- 230 m/s (There is no adding when relating these three variables.)
A: 7 m/s
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: A car is moving at 45. m/s for 3.0 seconds. How far has it traveled in that time?
- 140 m (Correct)
- 15 m (You divided when you should have multiplied.)
- 0.067 m (You divided when you should have multiplied.)
- 48 m (There is no adding when relating these three variables.)
A: 140 m
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: A boat is sails 1000 m while traveling at 20 m/s. How much time has elapsed?
- 50 s (Correct)
- 0.02 s (You divided the wrong way.)
- 20,000 s (You multiplied when you should have divided.)
- 1000 s (There is no adding when relating these three variables.)
A: 50 s
If right: Your answer is correct.
If wrong: Your answer is incorrect.

Q: Which of the following graphs shows an object that is moving at 20 m/s?
A: (a choice with no text)
If right: Correct.
If wrong: This graph shows an object that is stopped 100 m away from the reference point for the entire time.
If wrong: This graph shows an object that is moving at 4 m/s
If wrong: This graph shows an object that is STOPPED at 20 m away from the reference point for5 seconds.
If right: Your answer is correct.
If wrong: Your answer is incorrect.