energy
What is energy?
an object cannot move unless a ________ moves it
FORCE
forces can be described as:
pushes and pulls
When you push a medicine ball with 5N and the ball moves 0m. Is work being done?
No No, movement no work being done.
True or False: simple machines make work harder
FALSE - simple machines make work easier
The energy an object or particle has because of its motion
__________ describes how fast an object moves; distance over time.
Speed
in order to make an object go faster, slower, or change direction, what is needed?
FORCE
what is something that can store energy?
food, fuel, batteries...
Name 3 categories of things that do work
Wind, moving water, people, animals, machines
What is potential energy?
Stored energy that depends on the relative position, state, or configuration of an object within a system
Motion can be described by what 3 things:
direction, distance, speed
What is an example of an invisible force?
True or False: energy cannot be changed from one form to another
False: energy does change from 1 form to another, for example a pendulum switches between potential and kinetic energy.
What is a simple machine that you could use to lift a bucket up to a treehouse?
Pulley
__________ is the total sum of an object's kinetic energy and potential energy
Mechanical energy
____________ is the rate at which an object changes its velocity
Acceleration
____________ is the natural physical force that attracts any two objects with mass or energy toward each other.
Gravity
Compare identical balls released from the same height: one is thrown straight upward, and one is simply dropped. Which one has work done on it?
The ball thrown straight up. Kinetic energy is put into the ball.
What is a simple machine you'd find on a bicycle?
wheel and axle, lever in hand break
A stretched rubber band has what kind of energy?
Elastic Potential Energy
Raul rides his jet bike 15 meters east and then 10 meters south in 5 seconds. What is the velocity?
5 m/s Southeast (SE)
What is the net force of a book that is resting on a table that is experiencing a downward force on 500N?
0 N
Because the table is pushing up with a force of 500N.
Give an example of mechanical energy
riding a bike as you move the pedals
coasting down a hill on your bike
anything done by most machines when an object moves
A shovel or see-saw is what kind of simple machine?
lever