Newton's 1st Law
State Newton's 1st Law
F=ma
State Newton's 3rd Law
For every force, there is an equal and opposite force
How would I find displacement given the initial and final positions?
Displacement = Final Position - Initial Position
What is the unit of displacement?
meters (m)
What is inertia?
An object's tendency to resist changes in motion
How much force would a car engine need to accelerate a 3000 kg car at a rate of 3 m/s/s?
What are the 3 criteria for force pairs
1. Act simultaneously
2. Act on different objects
3. Are equal in magnitude but opposite in direction
How would I find velocity given displacement and time
Velocity = Displacement / Time
What are the units for mass and weight?
Mass: kg
Weight: N
Which is harder to accelerate: A 100 kg of feathers, or 75 kg of bricks?
The feathers
If I go to Neptune, which has an acceleration due to gravity of 11.09 m/s/s, what would my weight be (I have a mass of 70 kg)
776.3 N
A drop an apple from the air onto the ground. The Earth pulling down on the apple is the action force. Determine what the reaction force is
Reaction Force: Apple pulls up on the Earth
1. Given initial and final velocity
2. Given mass and force
1. Acceleration=(Final Velocity-Initial Velocity)/Time
2. Acceleration = Force/mass
What is the unit for velocity?
m/s
You are standing on a bus, when it moves forward. Use Newton's 1st law to explain what happens to you as the bus starts to move
Because you were at rest, and a force didn't act on you, your inertia will want you to stay stationary according to Newton's 1st law.
What acceleration would I produce if I pushed a 5 kg box with a force of 12 N?
What is 2.4
I step off my canoe, onto the dock. What are the action-reaction force pairs between me and the canoe?
Action Force: I push back on the canoe
Reaction Force: The canoe pushes me forward
How would I find the Force of an object given mass and acceleration?
F = ma
What is the unit for acceleration?
Explain why Newton's 1st Law is sometimes called the Law of Inertia
Inertia is the tendency to resist changes in motion, meaning that if no unbalanced force acts on it, inertia is not going to allow an object to move
A 12 kg block is being pulled with 20 N of force, but friction is resisting with a force of 8 N. With this information, what is the acceleration of the block?
a = Net Force / m
a = (20-8) / 12
a = 12/12
a = 1 m/s/s
Explain using Newton's 3rd Law how a rocket can propel in space, where there is no air
Reaction Force: Gas pushes forward the rocket
BONUS:
Make a list of all the vectors we've learned (4)
Displacement, Velocity, Acceleration, Force
What is the unit for force? (Include common unit, and the base SI units)
N = (kg*m)/s^2