How is Motion Measured ?
What is the difference between speed and velocity?
Velocity is speed AND direction
Name a force that can overcome inertia?
Friction, a push, pull
What is the amount of matter an object has?
Mass
Explain why riding a bike on the sidewalk is easier than riding a bike in grass.
SAMPLE ANSWER: Grass produces more friction.
What is a force and give 2 examples of forces.
A push or pull.
How can you calculate speed?
Total distance divided by time elapsed
Imagine you are riding a bike. What happens when you stop pedaling?
The bike will continue to move, but eventually stop because of friction.
Explain why the weight of an object is less on the moon than it is on Earth.
Gravity. There is less gravity on the moon.
Why does friction produce heat?
The rubbing together of objects produces heat.
Describe Newton’s 1st Law of gravity.
Inertia is the tendency of an object in motion to stay in motion or an an object at rest to stay at rest UNLESS an outside force changes it.
When an object changes speed, what is happening?
It is accelerating.
How does a seatbelt affect inertia?
It keeps your body in place.
How does gravity affect falling objects?
It makes them accelerate.
Name 2 ways to increase friction.
SAMPLE ANSWER:
Increase: rough surface, add brakes, sand, dirty, etc.
What is velocity?
Velocity is speed in a given direction
If a car goes 630 km in 9 hrs. What is the car’s speed?
70 km/hr
Imagine you are standing in a moving bus. How does inertia affect your body when the bus stops/brakes?
You move forward.
What are the two ways to increase gravity?
More mass = More gravity
Closer objects = more gravity
Name 2 ways to decrease friction.
SAMPLE ANSWER:
Decrease: water, oil/grease, add wheels, etc.
What is air resistance?
A type of friction caused by gas molecules to slow an object down
Name all 3 ways to change your velocity.
Change speed, change direction, or chance both speed and direction.
Give an example of a pair of forces working together.
SAMPLE ANSWER: skateboard and skateboarder; frog and lily pad; gravity and air resistance
Explain why 2 objects of different mass (baseball vs a basketball) hit the floor at the same time.
Gravity increases with mass.
Describe what streamlining is and when we would need it?
Streamlining is the process to make something more round or smooth to overcome friction. EX: a bullet train
A ___________ is a measure of force.
Newton.