work, energy and power Flashcards

revision (31 cards)

1
Q

What is the formula for work done?

A

Work done = Force x Distance x cos(θ)

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2
Q

True or False: Work done is a scalar quantity.

A

True

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3
Q

Fill in the blank: The unit of work done is ______.

A

Joule

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4
Q

What is the relationship between work and energy?

A

Work done on an object results in a change in energy.

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5
Q

Multiple Choice: Which of the following is NOT a unit of power? A) Watt B) Joule C) Horsepower D) Newton

A

D) Newton

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6
Q

What is the formula for power?

A

Power = Work done / Time taken

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7
Q

True or False: Power is defined as the rate at which work is done.

A

True

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8
Q

Fill in the blank: The SI unit of power is ______.

A

Watt

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9
Q

What is kinetic energy?

A

The energy an object possesses due to its motion.

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10
Q

What is the formula for kinetic energy?

A

Kinetic Energy = 1/2 mv²

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11
Q

Multiple Choice: Which of the following describes gravitational potential energy? A) Energy due to motion B) Energy stored due to position C) Energy of deformation D) None of the above

A

B) Energy stored due to position

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12
Q

What is the formula for gravitational potential energy?

A

Gravitational Potential Energy = mgh

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13
Q

True or False: Energy can be created and destroyed.

A

False

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14
Q

Fill in the blank: The principle of conservation of energy states that energy cannot be ______.

A

created or destroyed

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15
Q

What is the work-energy principle?

A

The work done on an object is equal to the change in its kinetic energy.

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16
Q

Multiple Choice: If the force applied to an object is in the same direction as the displacement, what is the value of θ in the work formula? A) 0° B) 90° C) 180° D) 45°

17
Q

What does it mean if work done is negative?

A

The force applied is in the opposite direction to the displacement.

18
Q

Fill in the blank: The total mechanical energy of an object is the sum of its ______ and ______.

A

kinetic energy, potential energy

19
Q

What does a watt measure?

A

A watt measures the rate of energy transfer equivalent to one joule per second.

20
Q

True or False: If no work is done on an object, its energy remains unchanged.

21
Q

What is the formula to calculate the work done against gravity?

A

Work done = mgh

22
Q

Multiple Choice: Which factor does NOT affect the amount of work done? A) Force applied B) Distance moved C) Direction of motion D) Time taken

A

D) Time taken

23
Q

What is elastic potential energy?

A

The energy stored in an object when it is compressed or stretched.

24
Q

What is the formula for elastic potential energy?

A

Elastic Potential Energy = 1/2 kx²

25
Fill in the blank: The work done by a constant force can be calculated using the area under the ______ vs. distance graph.
Force
26
True or False: Power is a vector quantity.
False
27
What is the effect of friction on work done?
Friction reduces the amount of work done by opposing the motion.
28
Multiple Choice: In a closed system, energy can be ______. A) Created B) Destroyed C) Transformed D) None of the above
C) Transformed
29
What is a practical example of power?
The rate at which a light bulb converts electrical energy into light.
30
Fill in the blank: In physics, energy is often classified into ______ forms.
various
31
What is the relationship between force, distance, and work done?
Work done is directly proportional to the force applied and the distance moved in the direction of the force.