Vocab
Force that opposes the sliding motion between two touching surfaces.
Friction
Which law of motion "states that the acceleration of an object is in the same direction as the net force on the object, and that the acceleration equals the net force divided by the mass?"
2nd law of motion
What type of friction would come into play if you were trying to push a skateboard over a surface?
Rolling friction
Attractive force between two objects that depends on the masses of the objects and the distance between themis _____________
Gravity
How can you calculate the net force of an object?
Take the mass of an object and multiple by acceleration
The amount of force that is needed to change the motion of an object is ________
momentum
Which law of motion states that "when one object exerts a force on a second object, the second object exerts a force on the first object that is equal in strength and opposite in direction."
3rd law of motion
What is the friction like force that comes into play when an object is falling?
air resistance
If I was swinging a bucket with water in it over my head in a circle, like I did in class, what force is preventing me from getting wet?
Centripetal force
What is the equation for calculating weight?
Mass times the acceleration of gravity
The highest speed a falling object will reach is called ________________
Terminal velocity
Which law of motion states that "an object at rest will remain at rest, and an object in motion will continue in motion with the same speed and direction unless acted upon by an external force."
Newton's first law
If you try to push a box, and it doesn’t move, there must be a force that is cancelling out your force. What type of friction is working against you?
static friction
Which of the following best describes why projectiles move in a curved path?
A. They have horizontal velocity and vertical acceleration
B. They have momentum that is less than the gravitational pull of Earth's rotation
C. They have mass
D. They have a perpendicular orbit to Earth
A. They have horizontal velocity and vertical acceleration
What is the equation for calculating momentum?
momentum=mass times velocity
Acceleration of an object toward the center of a curved or circular path. __________-
Centripetal acceleration
According to the 2nd law of motion, how do we calculate acceleration?
net force divided by mass
The term for the tiny points of contact where 2 surfaces stick together. These create friction.
microwelds
Why do feathers fall more slowly than apple?
Because the greater surface area catches more air resistance
What is the official unit for momentum?
kg · m/s.
Explain the difference between weight and mass?
Mass is the measure of matter in an object, weight is the gravitational force pulling on that matter.
If you jump on a trampoline, exerting force downward on it, what kind of force is exerted back at you AND which law of motion explains this? (must answer both parts)
An equal force. The 3rd law
Name all three types of friction
Sliding, rolling, and static friction
What is the acceleration of Earth’s gravitational force on an object in freefall?
9.8 m/s squared
You push yourself on a skateboard with a force of 40 N and accelerate at .5 meters per second squared. Find the mass of the skateboard if your mass is 58 kg
22 kg