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Questions and Answers
What is the rate at which work is done?
What is the rate at which work is done?
How much work is done to lift a 50kg barbell by 2m?
How much work is done to lift a 50kg barbell by 2m?
100J
Using a force to move an object through a distance is called what?
Using a force to move an object through a distance is called what?
work
Is there work done on the wall?
Is there work done on the wall?
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If the distance is 20m and the force is 5000N, how much work will be done?
If the distance is 20m and the force is 5000N, how much work will be done?
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Mechanical energy combines what two types of energy?
Mechanical energy combines what two types of energy?
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Kinetic energy is best described as what?
Kinetic energy is best described as what?
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What is the formula for gravitational potential energy at a specific height?
What is the formula for gravitational potential energy at a specific height?
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What cliff should the rock be thrown from to give it the greatest gravitational potential energy?
What cliff should the rock be thrown from to give it the greatest gravitational potential energy?
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How much power is produced when using 160J of energy in 8 seconds?
How much power is produced when using 160J of energy in 8 seconds?
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Simple machines can increase the amount of work done.
Simple machines can increase the amount of work done.
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What are the three classes of what?
What are the three classes of what?
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When potential energy is converted to kinetic energy, some energy leaves the system due to what?
When potential energy is converted to kinetic energy, some energy leaves the system due to what?
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How much kinetic energy does a 2.0 kg ball have that is moving at 4 m/s?
How much kinetic energy does a 2.0 kg ball have that is moving at 4 m/s?
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Reducing friction in a machine increases what?
Reducing friction in a machine increases what?
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_____ is an example of a lever.
_____ is an example of a lever.
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What law states that the total sum of mechanical energy in a closed system remains constant?
What law states that the total sum of mechanical energy in a closed system remains constant?
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What is the ideal mechanical advantage (IMA) for a ramp that is 6m long and 2 m high?
What is the ideal mechanical advantage (IMA) for a ramp that is 6m long and 2 m high?
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What is the AMA when the reel on a fishing rod uses 4N of forces to pull up a 24N fish?
What is the AMA when the reel on a fishing rod uses 4N of forces to pull up a 24N fish?
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The tire on a bicycle is an example of what?
The tire on a bicycle is an example of what?
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Energy has the same unit as ___________, which is _____________.
Energy has the same unit as ___________, which is _____________.
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The percentage of input work that is converted into output work is called what?
The percentage of input work that is converted into output work is called what?
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Study Notes
Power and Work
- Power is defined as the rate at which work is done.
- Work done on an object is the product of force and distance; for instance, lifting a 50kg barbell 2m results in 100 Joules (J) of work.
- Work is accomplished by applying a force to move an object over a certain distance.
Work and Force
- No work is done on a stationary wall, as there is no displacement.
- Calculating work: a force of 5000 Newtons (N) acting over a distance of 20 meters results in 100,000 Joules (J) of work.
Energy Types
- Mechanical energy is the sum of kinetic energy (energy of motion) and gravitational potential energy.
- Gravitational potential energy (PE) can be calculated using the formula PE = mgh, where m is mass, g is the acceleration due to gravity, and h is height.
- Kinetic energy (KE) can be calculated for a moving object; for a 2.0 kg ball at 4 m/s, KE equals 16 J.
Efficiency and Machines
- Simple machines do not increase the total amount of work done; rather, they make work easier.
- Efficiency refers to the percentage of input work converted to output work, impacting the performance of machines.
- Reducing friction in machines leads to increased efficiency.
Mechanical Systems
- In a closed system, the total sum of mechanical energy remains constant, as stated by the Law of Conservation of Energy.
- There are three classes of levers, which are tools that amplify force.
- An example of a lever is a mop, which can change the direction of applied force.
Inverted Mechanical Advantage
- The ideal mechanical advantage (IMA) for a ramp measuring 6m in length and 2m in height is 3.
- For a fishing rod's reel that uses 4 N of force to pull a 24 N fish, the actual mechanical advantage (AMA) is calculated to be 6.
Structural Components
- A tire is classified as a wheel and axle, demonstrating a simple machine.
- The unit of energy is the same as that of work, both measured in Joules.
Power Calculation
- Power output can be evaluated; using 160 Joules of energy in 8 seconds results in a power of 20 Watts (W).
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Description
Test your knowledge on the concepts of work and power with these flashcards. Learn definitions, formulas, and practical applications related to force, distance, and energy. A great way to reinforce your understanding of physics principles.
