SI Units
Standard Unit for Power is
Watts
What is the equation for Mechanical Energy?
ME = KE + PE
When music is playing on your Chromebook, what type of energy conversion takes place?
sonic energy to chemical energy
chemical energy to sonic energy
electrical energy to sonic energy
sonic energy to electrical energy
Electrical to Sonic Energy
____ is a form of energy that an object or a particle has by reason of its motion.
Kinetic Energy
Work is defined as _____ because its equation is ___________
the measure of energy transferred when a force is applied to move an object over a distance, W=F x d
the measure of energy stored in an object, P= W/T
the measure of the force applied to an object to make it move V = D/T
the measure of work transferred when a force is applied to move an object, GPE= m x g x h
the measure of energy transferred when a force is applied to move an object over a distance. W = F x d
Standard Unit for velocity is
METER PER SECOND (m/s)
Potential and Kinetic Energy
(Will count mechanical energy if the first two are mentioned)
Photosynthesis is the process in which _______ is converted to _____________ in the form of sugars. Glucose molecules (or other sugars) are constructed from water and carbon dioxide, and oxygen is released as a byproduct.
1. sound energy, light energy
2. light energy, chemical energy
3. thermal energy, nuclear energy
4. nuclear energy, chemical
Light Energy, Chemical energy
_____ is stored energy that depends on the relative position of various parts of a system.
Potential Energy
What is power?
Hint= Think about its equation
The rate at which work is done on an object
Standard Unit for GPE, KE, and ME is
Joules
Friction is a force that opposes motion. When friction is present, heat is usually generated. This decreases the mechanical energy of the object in motion. Why?
Some mechanical energy is converted to thermal energy.
The energy of flowing water can be harnessed to create electricity. Why is hydroelectricity considered to be renewable energy?
Flowing water is indefinitely available.
A 25 kg rock is perched on a cliff 20m above the ground. What is the potential energy of the rock?
4900 J
Percy does twice as much work as Jason in the same amount of time. Percy's power output is _____
twice Jason's power output
What is the standard unit for Work and Energy? Why do they have the same unit?
Joules
An amount of work takes the same amount of energy to do it, so energy is also measured in joules. Energy is the ability to do work
A 25 kg rock is perched on a cliff 20m above the ground. What is the mechanical energy of the rock?
4900 J
How do you generate an electric current?
A magnetic coil is moved in the presence of a magnetic field.
Describe the energy conversion of a car as it goes downhill from 100m to 0m.
The car’s potential energy is converted to kinetic energy because its speed increases as its elevation decreases.
Percy has a mass of 50 kg and accelerated at 5 m/s2 for 20 meters. This occurred over 10 seconds.
Calculate Work
5,000 Joules
Leo has a mass of 50 kg and accelerated at 5 m/s2 for 100 meters. This occurred over 30 seconds. What two units are needed to solve for the power of Leo over the 30 seconds of motion?
Work = Joules
Power = Watts
In a frictionless environment, according to the law of conservation of energy, what will happen to the total mechanical energy if the kinetic energy of the object decreases?
Mechanical energy will remain the same because potential energy will increase.
A measure of the average kinetic energy of the individual particles in an object is called _____.
temperature
convection
conduction
Temperature
A 25 kg rock was pushed on a cliff 20m above the ground. What is the maximum velocity of the rock before it hits the ground?
19.8 m/s
Percy has a mass of 50 kg and accelerated at 5 m/s2 for 20 meters. This occurred over 10 seconds.
Calculate Power
500 Watts