1. Lifting a Box:
* Description: You apply a force to lift a box vertically from the floor to a table.
* Work done: The work done is equal to the force you apply (against gravity) multiplied by the vertical distance the box is lifted.
* Formula: Work (W) = Force (F) x Distance (d)
2. Stretching a Spring:
* Description: You apply a force to stretch a spring from its equilibrium position.
* Work done: The work done is equal to the average force you apply multiplied by the distance the spring stretches.
* Formula: Work (W) = (1/2) * Force (F) x Distance (d) (because force increases as the spring stretches)
3. Moving a Crate Horizontally:
* Description: You push a crate across a smooth floor with a constant force.
* Work done: The work done is equal to the force you apply multiplied by the distance the crate moves horizontally.
* Formula: Work (W) = Force (F) x Distance (d)
4. Stopping a Moving Car:
* Description: You apply the brakes to slow down a car to a stop.
* Work done: The work done is negative, as the force you apply (friction from the brakes) acts in the opposite direction of the car's motion. The work done is equal to the force of friction multiplied by the distance the car travels while braking.
* Formula: Work (W) = - Force (F) x Distance (d)
5. Gravity Pulling an Object Down:
* Description: An object falls freely under the influence of gravity.
* Work done: Gravity does positive work on the object as it falls. The work done is equal to the force of gravity (weight of the object) multiplied by the distance the object falls.
* Formula: Work (W) = Force (F) x Distance (d)
Key Points:
* Work is done when a force causes a displacement. The force must have a component in the direction of the displacement.
* Work is a scalar quantity, meaning it only has magnitude (size), not direction.
* Work is measured in Joules (J).
* Positive work means the force and displacement are in the same direction.
* Negative work means the force and displacement are in opposite directions.
