Motion and Forces
Name one surface with a lot of friction and one with not a lot of friction
Not a lot: ice, smooth floors
How do you calculate an object's speed?
Distance divided by time
What is the force that pulls objects towards the earth?
Gravity
What is a push?
to use force to move someone or something away from you
Why would a ball go slower on grass than concrete?
The grass has more friction
What does a straight line represent on a speed-time graph?
Constant acceleration
What force acts against motion?
Friction
What is speed?
the rate at which someone or something moves or travels
Name two ways you can change how far a ball rolls when you roll it down a ramp.
Change the angle of the ramp
Change the surface of the ramp
Change the force of the ball going down the ramp
Sam went on a run and ran for an hour. He noticed that he ran a shorter distance in the last 30 minutes than the first 30 minutes. Why might this be?
He ran faster the first 30 minutes than the last 30 minutes.
If objects have different masses, what will happen if they are dropped at the same time?
They will hit the ground at the same time.
What is motion?
the action or process of moving or of changing place or position; movement
How could you figure out how much force was used on a ball?
See how far the ball rolled (the distance)
What does a horizontal line represent on a distance-time graph?
No motion
If an object is heavier, how will the force needed to move it also change?
It will require more force the heavier an object is
What is acceleration?
the rate at which the speed of a moving object changes over time
Below are shown times for a race:
Elijah: 150 meters in 55 seconds
Brayden: 150 meters in 90 seconds
Gabe: 150 meters in 70 seconds
Ricky: 150 meters in 60 seconds
Which student was the fastest?
What does a horizontal line represent on a speed-time graph?
Constant speed (no acceleration)
What are three ways you can describe the motion of an object?
Speed, distance, and direction
What is the difference between mass and weight?
Mass is how much matter in an object, weight is the measure of the pull of gravity