Work
What is the SI unit for work?
Joule (J)
What is the rate at which work is done called?
Power
How many class levels are there? What are their names?
3, First, second and third class levels
What is the numeric value of Cos horizontally?
1
What is the formula for work?
W=Fs
What is the formula for power?
P=W/t
Give one example of a first-class lever
Seesaw or scissors
What simple machine combines a wheel and axle?
A pulley or a wheel and axle
If the force is exerted at an angle to the displacement, what is the formula?
W = F ⋅ d ⋅ cos (θ)
What happens to power if the same work is done in half the time?
The power doubles
What type of lever has the load between the fulcrum and effort?
Second-class lever
A Jar lid is an example of what type of tool?
What must happen for work to be done on an object?
A force must act, and the object must move in the direction of the force.
If a person does 1000 J of work in 20 seconds, what is their power output?
50 W
What does a fixed pulley do?
Changes the direction of the applied force
What is the physical meaning of displacement?
The shortest distance between the initial and final positions, including direction.
A worker applies a 100 N force to move a crate 6 m horizontally. How much work is done?
600 J
A motor does 900 J of work in 15 seconds. What is its power?
60 W
How does a movable pulley reduce effort?
It reduces the amount of force needed by sharing the load.
Explain the main function of a fixed pulley
It changes the direction of the applied force but does not reduce the force needed.