Work and Power
What are the units for Work?
Joules (J)
Identify the dependent variable for the experiment that answers the following question:
“What happens to the elastic potential energy stored in a spring when the spring constant is being changed?”
Elastic Potential Energy
What type of energy is stored in an object based on it's height?
Potential Energy (PE)
What type of energy is stored in springs?
Elastic Potential Energy
What concept states that energy cannot be created or destroyed, it can only be transferred or change forms.
Conservation of Energy
What happens to power when you increase the work done by a system?
Power also increases (direct relationship)
Identify the independent variable for the experiment that answers the following question:
“What happens to the elastic potential energy stored in a spring when the spring constant is being changed?”
Spring Constant
If an object has a Potential Energy of 200 j and Kinetic energy of 10 j, what is the mechanical energy of the object?
210 j
If spring 1 has a displacement of 1m and spring 2 has a displacement -1m, which spring has more energy?
They have the same amount of energy.
What type of energy will always stay as an object changes motion and height if no additional force is added?
Mechanical Energy
What units are used to measure power?
Watts (W)
When comparing two variables, any other variables should be kept ____________.
Constant
If you double an objects height, this happens to your Potential Energy.
It also doubles (direct relationship)
What is the difference between Spring 1 that is not flexible and a Spring 2 that is very bendy?
The second spring has a lower spring constant.
If an object has a mechanical energy of 400j and has a kinetic energy of 250j, what is the object's potential energy?
150 j
What happens to power when you increase time?
Power decreases (inverse relationship)
Create a hypothesis to answer the following question:
“What happens to the elastic potential energy stored in a spring when the spring constant is being changed?”
If the spring constant increases, then the elastic potential energy will also increase.
An object is rolling on a flat surface on the ground.
What percent of its energy is potential and kinetic?
PE= 0% KE=100%
A spring is displaced by 0.4 m by a box that has a mass of 50 kg. The spring constant is 10 N/m. What is the energy stored in the spring?
0.8 j
If a box started falling off a building, halfway down, what would be the percent of the energy that was KE, PE, and ME?
KE= 50% PE=50% ME=100%
If you do 2000 Joules of work in 5 seconds, what is the power produced?
400 watts
If you measure the following spring constants in an experiment, what is your average spring constant? Include the correct units.
11.31 3.322 10.23
8.29 N/m or 8.287 N/m
An object starts moving at 30 m/s and moves up a ramp unit until it comes to a stop.
The energy the object started with was _____ and was converted to ____.
Started with 100% KE and ended with 100% PE.
A box is attached to a spring at the bottom of a ramp. The box is released from the spring and it travels up the ramp unit it comes to a stop. What percent of the energy is PE, KE, and U at the final position of the box?
U=0% PE= 100% KE=0%
An object that has a mass of 10 kg starts with a mechanical energy of 300 j, and all of the energy is converted to potential energy. Calculate the height of the object.
3.06 m