Pg:- 140,141,142,143
Ch:- 8
Work is the measure of energy transfer when a force is applied to an object, causing it to move in the direction of the force.
Formula for Work:
W = F ⋅ d
Where:
W = Work (measured in joules, J)
F = Force applied (in newtons, N)
d = Displacement of the object (in meters, m)
Key Points:
Work is only done if the object moves due to the force.
If the displacement is zero, no work is done, even if a force is applied.
The force must have a component in the direction of displacement.
Power is the rate at which work is done or energy is transferred over time. It shows how quickly work is performed.
Formula for Power:
P = W/t
Where:
P = Power (measured in watts, W)
W = Work done (in joules, J)
t = Time taken (in seconds, s)
Key Points:
Power tells how fast energy or work is used or produced.
The SI unit of power is the watt (W), where 1 W=1 J/s
Example:
If a machine does 100 joules of work in 5 seconds, the power is: P=100/5 = 20 W
Related Concept:
Kilowatt (kW): 1 kilowatt = 1000 watts.
Horsepower (hp): Another unit of power, 1 hp ≈ 746 watts.
What is the formula for calculating power?
How do you differentiate between work and power?
What are some examples of work and power in everyday life?
How does the concept of mechanical advantage relate to work and power?
What is the relationship between energy, work, and power?
How do you calculate the power output of an engine?