CH - Work Energy and Power
1. Work:
● De nition: In physics, work is de ned as the transfer of energy that occurs
when an object is moved against a force, or when a force acts on an
object over a certain distance.
● Formula: Work (W) = Force (F) x Distance (d) x cos(θ), where θ is the
angle between the direction of force and the direction of displacement.
● Units: The SI unit of work is the joule (J), which is de ned as the work
done when a force of one newton (N) is applied to an object and displaces
it by one meter (m) in the direction of the force.
2. Energy:
● De nition: Energy is the ability to do work or the capacity to cause change.
It can exist in various forms such as mechanical, thermal, chemical,
electromagnetic, etc.
● Types of energy:
● Kinetic energy (KE): It is the energy possessed by an object due to
its motion. The formula for kinetic energy is KE = 0.5 x mass (m) x
velocity (v)^2.
● Potential energy (PE): It is the stored energy possessed by an
object due to its position or condition. There are several types of
potential energy:
● Gravitational potential energy: It is the potential energy
associated with the position of an object in a gravitational
eld. The formula for gravitational potential energy is PE =
mass (m) x gravitational acceleration (g) x height (h).
● Elastic potential energy: It is the potential energy stored in a
stretched or compressed elastic material, such as a spring.
The formula for elastic potential energy is PE = 0.5 x spring
constant (k) x displacement (x)^2.
● Chemical potential energy: It is the potential energy stored in
the chemical bonds of a substance.
● Units: The SI unit of energy is also the joule (J).
3. Power:
● De nition: Power is the rate at which work is done or the rate at which
energy is transferred or converted. It measures how quickly work is done
or energy is transferred.
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1. Work:
● De nition: In physics, work is de ned as the transfer of energy that occurs
when an object is moved against a force, or when a force acts on an
object over a certain distance.
● Formula: Work (W) = Force (F) x Distance (d) x cos(θ), where θ is the
angle between the direction of force and the direction of displacement.
● Units: The SI unit of work is the joule (J), which is de ned as the work
done when a force of one newton (N) is applied to an object and displaces
it by one meter (m) in the direction of the force.
2. Energy:
● De nition: Energy is the ability to do work or the capacity to cause change.
It can exist in various forms such as mechanical, thermal, chemical,
electromagnetic, etc.
● Types of energy:
● Kinetic energy (KE): It is the energy possessed by an object due to
its motion. The formula for kinetic energy is KE = 0.5 x mass (m) x
velocity (v)^2.
● Potential energy (PE): It is the stored energy possessed by an
object due to its position or condition. There are several types of
potential energy:
● Gravitational potential energy: It is the potential energy
associated with the position of an object in a gravitational
eld. The formula for gravitational potential energy is PE =
mass (m) x gravitational acceleration (g) x height (h).
● Elastic potential energy: It is the potential energy stored in a
stretched or compressed elastic material, such as a spring.
The formula for elastic potential energy is PE = 0.5 x spring
constant (k) x displacement (x)^2.
● Chemical potential energy: It is the potential energy stored in
the chemical bonds of a substance.
● Units: The SI unit of energy is also the joule (J).
3. Power:
● De nition: Power is the rate at which work is done or the rate at which
energy is transferred or converted. It measures how quickly work is done
or energy is transferred.
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