Time, Distance, Speed
Which is a unit of time:
A. centimeters
B. miles
C. decades
D. miles per hour
C. decades
What does it mean when an object has positive acceleration?
An object is speeding up.
*Speed Graph Picture* What type of graph is this?
Constant Speed
What does it mean when forces acting on an object are balanced?
-The forces are equal
-The object is at rest/not moving
-The object is at a constant speed
What happens to an object with more mass when you push it with the same force as a lighter object?
It will not go as far and go slower.
What is a unit of distance:
A. miles
B. meters per second
C. years
D. minutes
A. miles
What is another name for negative acceleration?
Slowing Down.
*Speed Graph Picture* What type of graph is this?
Negative Acceleration
If a box is not moving, are the forces on it balanced or unbalanced?
Balanced
If two objects are pushed with the same force, which one will move faster: the heavier one or the lighter one?
The lighter object.
A runner covers 12 meters in 3 seconds. What is the runner’s speed?
4 meters per second.
If a car is driving down a straight road going a speed of 60 mph the whole time, what type of motion is the car showing an example of?
Constant speed.
*Speed Table Picture* What type of table is this?
Constant Speed
What happens to an object when unbalanced forces act on it?
-The forces are unequal
-It causes a balanced object to move
How does increasing the mass of an object affect the force needed to change its motion?
You will need to use more force to move the object.
A car travels 150 kilometers in 5 hours. What is the car’s speed?
30 kilometers per hour
A bike increases its speed from 5 m/s to 15 m/s in 4 seconds. Is this positive or negative acceleration? How do you know?
Positive acceleration because the speed is increasing.
*Speed Table Picture* What type of table is this?
Slowing Down
A tug-of-war rope doesn’t move even though both teams are pulling. What kind of forces are acting on the rope? Explain.
Balanced because each side is using the same amount of force.
A heavy box and a light box are both pushed with the same force. Explain why the light box accelerates more.
The light box does not have as much mass, meaning there is not as much force keeping the box down.
A boat moves 1800 miles in 20 hours What is the boat’s speed in miles per hour?
90 miles per hour.
A bicycle rider applies the brakes and the bike goes from 20 miles per hour down to a stop in 5 seconds. What type of motion is this? Explain your answer.
Slowing down. The bicycle is coming to a stop.
*Speed Graph Picture* What is happening from Point _ to Point _
At Rest
Explain why a book resting on a table experiences balanced forces,.
The forces around the book are equal causing it to stay still.
Two cars are pushed with the same amount of force. Car A has a mass of 1,000 kg, and Car B has a mass of 2,000 kg. How does the acceleration of Car A compare to Car B? Explain why using what you know about mass and motion.
Car A has less mass than Car B. This means Car A will go further and faster than Car B.