Equations
Jason pulls a box with a force of 3N, and John pulls the box from the opposite side with a force of 4N. Ignore friction. Which way does the box get pulled?
Towards John
Explain the relationship between work and energy.
Force is made by energy and you need force for work.
What is the unit for force?
N (kgm/s^2)
What is velocity?
Speed in a specific direciton
What is acceleration?
The relate at which velocity changes with time
Goldie the Goldfish, a speed swimmer, loves to race around the park's pond, which is 0.5 miles around. If she can swim 20 laps around the track in 2 hours, what is her average speed?
5 meters per hour
Which force keeps Venus in orbit around the sun?
Gravity
What is the unit for momentum?
Newton
What is a vector?
a quantity that has both size and direction
What is an inclined plane?
a simple machine that is a sloping surface
If you push a cart with a force of 70N for 3 meter, how much work is done?
210 joules
If you push very hard on an object but it does not move, have you done work?
No, because the box does not move
What is the unit for work?
Joule (n x m)
What is position?
describes the location of an object
What is a machine?
any device that helps people do work
A truck with a mass of 7000kg is traveling north on a highway at a speed of 20m/s. A car with a mass of 3000kg is traveling south on the same highway at a speed of 30m/s. Which vehicle has more kinetic energy?
The Truck
What is mechanical energy?
the energy possessed by an object due to its motion or position
Meter
What is a reference point?
a location to which you compare other locations
What is air resistance?
friction due to air
Which takes more power: using 15N to lift a ball 2m in 5s or using 100N to push a box 2m in 1 minute (60 seconds)?
Using 100N to push a box 2m in 1 minute
How is friction a force?
Friction is a force that resists the motion between surfaces in contact.
Pascal
You can only describe position if there is a...
Reference point
What's an inertia?
the resistance of an object to a change in the speed or the direction of it motion