CHAPTER 2 JEOPARDY

What is the unit we use for speed?

m/s

What is the term for speed and direction?

Velocity

Acceleration is a change in what over time?

velocity

Give an example of when a car can have constant speed but not constant velocity.

When it is changing direction

What would be your speed if you ran 20 m down the hall in 4 s?

5 m/s

What causes objects to speed up as they fall?

gravity

What is the value of gravity that we will use in this class?

10 m/s²

Why does a crumpled up piece of paper fall faster than a flat piece of paper?

It has less air resistance

If the speed of a car is 4 m/s and it travels for 8 s, what distance has it moved?

32 m

If an object has negative acceleration, what is happening to it?

It is slowing down

How much time does an object traveling at 10 m/s need to travel 80 m?

8 s

What equation do we use to find the distance a falling object has traveled?

d = ½ gt²

What is your velocity if you are sitting still?

zero

What does it mean to say that speed is relative?

The speed is relative to where we are. We might be sitting still at our desks but we are in motion on the Earth therefore, our speed of zero is relative to the motion of the Earth.

What happens to the speed of a falling object? Does it increase, decrease, or remain constant?

It increases

As an object falls its speed increases. How does the amount that the speed increases change as it falls? Does it increase, decrease, or remain the same?

It remains the same. The speed increases by 10 m/s every second.

A ball is thrown straight up. What is its speed at the top of its path?

zero

A car starts from rest. After 3 s its velocity is 9 m/s. What is the car’s acceleration?

3 m/s²

What does each letter stand for in the equation

a = (vf – vi)/t

a = acceleration vf = final velocity vi = initial velocity t = time

Do not solve the following problem. Pick out the final velocity: A car moving at 6 m/s comes to a stop in 4.3 s. What is the car’s acceleration?

vf = 0

Is 4 m/s south a speed or velocity?

velocity

What unit is distance measured in?

m

A monkey drops from a tree. After 3s how fast will it be moving?

30 m/s

What is the acceleration of a car that travels in a straight line at a constant speed of 100 km/h?

zero

What day is your test?

Thursday

Name one lab we have done in here

Bowling ball lab Speed lab outside Water bottle rocket lab

Does air resistance increase or decrease the acceleration of a falling object?

decrease

How is instantaneous speed different from average speed?

Instantaneous speed is how fast something is moving at one instant. Average speed accounts for all the different speeds an object may travel.

What is the acceleration of a ball that is thrown up at the top of its path?

10 m/s²

A child drops a toy off a balcony. If it takes 3 s for the toy to hit the ground, how tall is the balcony?

45 m

By how much does a falling objects speed change each second?

10 m/s each second

If you throw an object up it will slow down on the way up. By how much does its speed slow down each second on the way up?

10 m/s each second

What equation do we use if an object is moving at a constant velocity?

S = d/t

If you drop a penny and a feather at the same time from the same height in a vacuum, which will hit the ground first?

They will hit at the same time.

A runner runs at a constant speed of 5 m/s. After 3 minutes how far will the runner have traveled? (be careful about the minutes)

900 m

A construction worker drops a hammer off of a building that is 45 m tall. How much time will it take the hammer to hit the ground?

3 s

If an object falls freely for 5 seconds, what is its velocity?

50 m/s

Which of the following is not a velocity? 45 m/s up 17 mph right 4 km/h 66 m/s southeast

4 km/h

Is the value of gravity different for different objects?

No, it is always 10 m/s²

The End