Forces
How much force is needed to jump into the air using your legs?
about 1,000N
What is energy?
The capacity to do work
What is work?
Release of energy in a moving object.
Name five scalar quantities.
1. distance
2. speed
3. volume
4. mass
5. temperature
6. time
7. power
8. energy
What is momentum?
A property of moving objects.
What is inertia?
Inertia is the tendency of an object to resist changes in motion.
How many calories are in one Joule?
4184 calories
What is power?
Work done in a certain amount of time.
Name five vector quantities.
1. displacement
2. velocity
3. acceleration
4. force
5. momentum
What is impulse and its three equations?
A change in momentum.
1. J = Pf - Pi
2. J = m(vf- vi)
3. J = Ft
What does it mean when the resultant force of a system is zero?
The object is either at rest or is moving at a constant velocity.
Explain the Law of Conservation of Energy.
Energy can be converted from one form into another but the total amount will remain constant.
According to the equation W = Fd, what is one Joule equal to?
1J = 1N x m
Rearrange the equation W = Fd to solve for force.
F = W/d
Describe conservation of momentum and the equation that is used to solve for it.
The total amount of momentum in a closed system will always remain constant.
Equation: Pinitial = Pfinal
What are Newton's three laws regarding motion?
1. An object will not change its motion unless a force acts on it.
2. F = ma
3. For every action, there is an equal and opposite reaction.
Name four energy outputs from a rocket launch.
1. kinetic energy
2. thermal energy
3. sound energy
4. light energy
According to the equation P = W/t, what is one watt equal to?
1watt = 1 J/s
What does a positive increasing slope mean on a distance vs. time graph?
The object is accelerating and moving away.
What are the three types of collisions?
1. Elastic Collision
2. Inelastic Collision
3. Explosion
250N is applied to a 25kg box. What is the acceleration of the box?
a = 10m/s²
A 1,500kg car moves at 13m/s. Find its kinetic energy.
KE = 126,750J
A couch is pushed 8m across a living room with a force of 200N. How much work is done on the couch?
What does a negative slope mean on a velocity vs. time graph?
Deceleration (slowing down)
A 60kg object begins at rest and accelerates to a speed of 15m/s. Find its impulse.
900J