Simple Machines
Crowbars, Seesaws and Wheelbarrows are all examples of this type of simple machine that is made of a fulcrum and a rigid beam
What is a Lever?
Energy and Work both have this unit.
What are Joules?
A motor does 100 J of work in 5 seconds, how much power does it apply during that time?
20 W
A rock has 10 J of gravitational energy, then after being launched from a catapult, it has 40 J of mechanical energy and 15 J of gravitational Energy, how much work did the catapult do to the rock?
What is 45 J of work?
Axes, Knives, and scissors all contain this simple machine whose purpose is to split objects
What is a wedge?
All Energy that involves motion is this type of energy
What is Kinetic Energy?
A crane on Earth lifts a 200 kg crate 20 m off the ground. Find the Work done by the crane on the crate
39,200 J
When something/someone does work, this (increases, decreases, stays the same) happens to their energy.
What is decreases?
Give a new example (one not already mentioned by a presented or Mx. Wilcox) of a simple machine, and say which simple machine it is
Great Job!
This type of energy can be thought of as an object's "capacity to fall", and increases as the object is raised in the air.
What is gravitational Energy
In the past million years, the total energy in the entire universe has been doing this (increasing, decreasing staying the same)
What is staying the same?
A 2kg ball is dropped from 5 m above the ground on Earth. How fast does it fall right before hitting the ground (h = 0)?
9.9 m/s
When a wheelchair ramp is made steeper, users are required to use more force to pull themselves up. This (increase, Decrease) has happened to the Mechanical Advantage of the inclined plane.
What is decreased?
This type of energy is stored by stretching materials that... stretch.
What is Elastic Energy?
A sailor lifts a crate with a mass of 50 kg, 12 m off the ground in 10 seconds. How much power does the sailor apply to the crate in that time?
588 W
A catapult is powered by a spring with spring constant (strength of spring) of k = 1000 N/m, stretched 2 m. All of the elastic energy will be converted to mechanical energy in the 10 kg projectile. How fast will the projectile launch?
20 m/s
When a simple machine's Mechanical Advantage is "Ideal" that means none of this is lost due to friction, vibrations, or other means.
What is energy? (or work, or power)
As an object falls, it loses this type of energy and gains this type of energy.
What are Gravitational Energy (Loses) and Mechanical Energy (Gains)?
A 1000 kg car accelerates from rest to 20 m/s in 10 seconds. Find the Power applied by the engine on the car in this time.
What is 20,000 W
Mx. Wilcox sleds down a hill on Earth. The hill is 20 m tall, and all of their gravitational Energy becomes Kinetic Energy at the bottom of the hill.
How fast does Mx. Wilcox Travel at the bottom of the hill?
19.8 m/s