Period 5 Kinematics Review

A distance does not include the direction. Look for ones that don't have up, down, left, right, +,-.

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.

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.

The acceleration due to gravity on earth is -9.8 m/s^2 or -9.8 m/s/s.

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.

Because the object is moving at a constant velocity, we use the equation v=d/t

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.

Look at the signs on the positive and negative. If they are different, the object is slowing down.

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.

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.

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)

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.

You are accelerating when you are speeding up, slowing down, or changing direction.

Look at the signs on the positive and negative. If they are the same, the object is speeding up.

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

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.

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.

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.