Newtons Laws
A push or a pull is better known as ______.
Force
define: net force
total force acting on an object
If forces are applied and they equaled out, they are _________ forces.
Balanced
This states that an object’s motion will not change unless an unbalanced force acts on the object.
What is Newton's First Law?
IF something is moving at a constant speed, are the forces balanced or unbalanced?
balanced
The unit of force is this.
What is the Newton?
What force would you need to move a mass of 2 kg at a rate of acceleration of 3 m/s/s?
6 Newtons
What causes a ball that has been kicked across the ground to stop?
Friction
What frictional force would I need to have an object travel at constant velocity?
Force applied = 40 N
Mass = 3000-kg
Acceleration = 3 m/s2
40 N
As you are riding a bike down a hill, you notice a rhinoceros iguana and PUSH DOWN REALLY HARD on your breaks. You fly over the handle bars and smack the pavement.
Newton's First Law
The attractive force that exists between all objects that have mass?
What is gravitational attraction?
F = m x a
Which Newton's Law does this apply to?
Newton's 2nd law
What is the force required to move a 100 kg refrigerator at 3 m/s/s?
300 N
If a box is being pushed with a force of 5 N to the right and also being pushed, in the opposite direction, with a force of 12 N, what would you net force be?
(answer / direction for credit)
7 N left
Which object has more inertia?
* A 1,000-kg car traveling at 2,000,000 mph
OR
* A 20,000-kg house that is not moving
The 20,000-kg house
A book is resting on a table. You start to apply 10 N of force to the book AND IT DOES NOT move. What is the NET FORCE on the book at this moment?
0 Newtons!!!! The book is not moving.
As the fuel burns, gases push against the rocket, moving it upward.
Newton's 3rd Law
If you put a notecard on a cup, and a penny on top of the notecard and flick the card so the penny falls in the cup, which force is acting on the penny so it falls down?
gravity
This Newton's law states that for every action, there is an equal and opposite reaction.
What is Newton’s Third Law?
Mass = 50 kg
If someone is pushing a box with 15 Newtons of force to the right, and another person is pulling the box (right) with 5 N of force, what is the net force?
20 N to the right
A 60-kg skateboard is accelerating at 2 m/s2. What is the FRICTIONAL FORCE to get the skateboarder to travel at constant speed?
Force applied = force friction to move at constant speed. Therefore, 120 N.
40 N <----Box----->100 N
What is the NET FORCE (and indicate the direction for full credit).
60 N to the RIGHT
A car (1000-kg) and a train (5,000-kg) are going the same speed. Then you apply the same force to both vehicles and you notice the car is still accelerating more.
Newton's 2nd Law
What is the rate of gravity on earth (units too)!!!
9.8 m/s/s
or
9.81 m/s2
Units for acceleration?
Meters per second squared
m/s/s
m/s2
As you are playing TUG-OF-WAR, your team is pulling (left) with a force of 200 N. The opposing team is pulling (right) with a force of 199 N. Which team will win and what direction will the team be going as they win? (You need to answer both parts to get this correct)
Your team wins by pulling the other team to the LEFT.
A 100-kg person goes skydiving off the coast of Maryland! They were wondering what the Net Force would be on them (ignoring air resistance) as they are free-falling.
F = m x a
F = 100-kg x 9.81 m/s2
F= 981 N
According to Newton’s Second Law, if the force increased but the mass remained the same, what happens?
The objects acceleration increases.
A 2.0-kg object that weighs 20 N is released on PLANET Q. What is the acceleration due to gravity on PLANET Q?
a = F / m
a = 20 N / 2.0-kg
10 m/s2
A tennis ball is thrown directly at a basketball and when they collide, you notice that they both go in opposite directions.
Newton's 3rd law.
As you free-fall, you will reach a maximum speed because of air resistance. What is the term for when you reach max. speed?
Terminal Velocity
The standard unit of mass is this.
kilogram
As you are pushing a couch (50kg) with a force of 400 N, you hit a patch of carpet that impacts with 100 N, what is the acceleration of the couch as you are moving along the carpet?
6 m/s/s