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Forms of energy
Defenitions
Formulas
Forces in Fluids
Practice Questions
100
A compressed spring or stretched elastic are examples of what form of energy?
Elastic energy
100
What is the definition for energy?
the ability to do work OR effect change
100
What is the formula for Energy Efficiency?
Energy efficiency = useful energy / energy consumed x 100
100
What is a fluid and what are its characteristics? (give me an example)
Fluid is a substance of variable shape and it assumes the shape of it's container (ex:bathtub). An example of a fluid would be milk.
100
If you walk at a constant pace (speed) what is the resultant force of your travel?
the resultant force is zero because the motion is not changed (remains the same)
200
The sun is an example of what 2 forms of energy?
Thermal and Radiation Energy
200
What is a force?
An action that can change the motion of an object, or deform the object, by pushing or pulling on it.
200
What is the formula for velocity?
V = d/t Velocity Distance Time
200
What are the 2 factors which have an impact on pressure within a liquid?
depth and density
200
What is the resultant force 115N---------------> <---------------35N
80N ---------->
300
Water (rivers, waterfalls) can be used in what form of energy?
Hydraulic energy
300
What is thermal energy?
The energy contained in a substance, determined by the number of particles in the substance and their temperatures.
300
What is the formula for WEIGHT (W)?
W=mg Weight (in Newtons) m=mass in kilograms (Kg) g=acceleration due to gravity
300
What is buoyancy?
Buoyancy is the upward force exerted on an object causing it to float. Buoyancy force is equal to the amount of water displaced by the object.
300
What is the resultant force? 35N----------> <---------30N
5N-------->
400
Why is energy said to be constant?
Because it cannot be created or destroyed (The law of conservation of energy), it can only be transformed and transfered.
400
What is friction?
a force that prevents two objects from slipping over each other when they come into contact.
400
What is the constant of gravity? In m/s2
the constant for gravity if 9.81 m/s2
400
What are the 3 principles which were discussed in this chapter?
Pascals Principle Archimedes Principle Bernoulli's Principle
400
If an object weight 113 N what is the weight of the water which must be displaced for the object to float?
113N must be the weight of the water displaced so that the buoyancy force is equal to the weight of the object.
500
In writing: please give me one example of enery transfer and one example of energy transformation.
Photosynthesis (transformation) Energy from heating system (transfer) Food provides energy to body (transformation)
500
In writing tell me the difference between MASS and WEIGHT.
Mass = the measure of quantity of matter in an object. Weight= the measure of gravitational force acting on an object.
500
What is the formula for finding pressure in a fluid?
P=F/A P= pressure (Pascals) F=force perpendicular to surface (Newtons) A- area in the surface subjected to the foce (m2)
500
In your own words describe how a boat floats?
The fact that the buoyancy force is equal to the gravitational force (weight) of the boat.
500
To perform work equal to 3 500J, a machine consumes 5000J. What is the energy efficiency of this machine?
Energy Efficiency=useful energy/energy consumed x100 EE= 3500J/5000 x100 70%