1.
Which of the following is a velocity?
Correct Answer
C. -5.0 m/s
Explanation
A velocity needs a direction, which is +,-,up, down, left, right.... -9.8 m/s/s isn't it because that's an acceleration (m/s/s) not a velocity (m/s)
2.
What is the acceleration due gravity?
Correct Answer
A. -9.8 m/s/s
Explanation
The acceleration due to gravity on earth is -9.8 m/s^2 or -9.8 m/s/s.
3.
You drive 100 mi North and then 20 mi south. What is your distance?
Correct Answer
D. 120 mi
Explanation
When finding a distance, you don't care about direction. Just add up the two displacements and make sure you don't include the direction.
4.
You drive 100 mi North. You then drive 20 miles south. What was your displacement?
Correct Answer
A. 80 m North
Explanation
You are talking about displacement so you care about the direction. Because you are moving north and then south, you subtract your two values. 100-20=80. You need to include the direction because with displacement you care about your direction. Overall you went more north than south, so the direction of your displacement is north.
5.
Chose all the the scenarios where you are accelerating:
Correct Answer(s)
C. You are rounding a corner going a constant 20 m/s.
D. You see a beautiful, new, smiling stranger, who makes you slow to a stop.
Explanation
You are accelerating when you are speeding up, slowing down, or changing direction.
6.
Choose the situations where the object is speeding up:
Correct Answer(s)
A. Positive velocity, positive acceleration
D. Negative velocity, negative acceleration
Explanation
Look at the signs on the positive and negative. If they are the same, the object is speeding up.
7.
Choose the situations where the object is slowing down:
Correct Answer(s)
B. Positive velocity, negative acceleation
C. Negative velocity, positive acceleration
Explanation
Look at the signs on the positive and negative. If they are different, the object is slowing down.
8.
You stand at the top of the highest building in the world, the Burj Kalifa, which is about 818 m tall. Imagine there is no air to get in the way. You drop a penny. How long would it take the penny to hit the ground?
Correct Answer
C. 12.9 s
Explanation
You need to remember for these that displacement (818 m) is down so it is negative (-818 m). Acceleration is on earth and due to gravity so a=-9.8m/s/s. Your initial velocity is 0 m/s. You should chose the second equation on your constant acceleration sheet.
If you got the first answer, you forgot to take the square root.
If you got the second answer, you forgot to divide by multiply by 2
If you got the fourth answer, you forgot to divide by 9.8
9.
The object in the graph on the left is:
Correct Answer
A. Speeding up in the positive direction
Explanation
This is where you want to draw the three circles, lay your pencil down on the line, and see how the velocity changes. The velocity is the slope of the line. At first, it is very slightly positive. As time goes on, it gets more and more positive. In other words, the object has a greater and greater positive velocity.
10.
The object in the graph on the right
Correct Answer
C. Speeding up in the negative direction
Explanation
This is where you want to draw the three circles, lay your pencil down on the line, and see how the velocity changes. The velocity is the slope of the line. At first, it is very slightly negative. As time goes on, it gets more and more negative. In other words, the object has a greater and greater negative velocity.
11.
Describe the motion of the object in this graph.
Correct Answer
C. If is moving at a constant velocity, then accelerating.
Explanation
This is a velocity time graph, so the farther you go from the x axis, the faster you are going. At first, you are going a nice steady, 2 m/s. You keep doing this for 4 seconds. You then accelerate, faster and faster, up to 10 m/s.
12.
During the first 4 seconds, what is the acceleration of the object?
Correct Answer
C. 0 m/s/s
Explanation
This is a velocity vs. time graph. On this type of graph, the slope equals the acceleration. During the first four seconds, the graph is flat, so the slope is zero and there is no acceleration. The units on acceleration are m/s/s.
13.
What was the total displacement of the object in this graph?
Correct Answer
A. 48 m
Explanation
This is a velocity vs. time graph. You can find the displacement of the object by finding the area under the line. Break it up into rectangles and triangles, then use the area equations to find the answer. Refer to your notes if you need help.
14.
Match the velocity graph to its acceleration graph.
Correct Answer
A. A
Explanation
This is a velocity vs. time graph. To find the acceleration, you just need to look at the slope. In this case, you have a negative slope. The answer is therefore A. Look at your notes if you are lost.
15.
A zebra is being chased by a lion. It is running constantly at its top velocity +22 m/s. How long will it take the zebra to run 68 m?
Correct Answer
D. 3.1 s
Explanation
Because the object is moving at a constant velocity, we use the equation v=d/t
16.
A plane goes from flying 220 m/s to stop while experiancing an acceleration of -16 m/s/s. How far does the plane travel before it comes to a stop?
Correct Answer
D. 1512.5 m
Explanation
In this case, your initial velocity is 220 m/s. Your final velocity is 0 m/s. The acceleration was -16 m/s/s. You would chose the third constant acceleration equation.
17.
During the last 4 seconds, what is the acceleration of the object?
Correct Answer
A. 2 m/s/s
Explanation
This is a velocity vs. time graph. On this type of graph, the slope equals the acceleration. Use the slope equation to find the slope, which is 2 m/s. The units on acceleration are m/s/s.
18.
Which of the following is a distance?
Correct Answer
C. 11 m
Explanation
A distance does not include the direction. Look for ones that don't have up, down, left, right, +,-.