work and energy flashcard

Power is the rate at which work is done or energy is transferred. It depends on both the force applied and the speed at which the work is done.

Efficiency can be calculated using the formula: $$\text{efficiency} = \frac{\text{useful energy}}{\text{total energy}} \times 100$$ .

This principle, known as the law of conservation of energy, states that energy can only be transformed from one form to another, but the total energy remains constant.

Mechanical advantage is calculated by dividing the load force by the effort force. For example, if the load is 100 N and the effort is 20 N, the mechanical advantage is $$\frac{100}{20} = 5$$ .

As the ball falls, it loses potential energy and gains kinetic energy.

Kinetic energy is the energy an object possesses due to its motion, calculated using the formula: $$KE = \frac{1}{2}mv^2$$ , where m is mass and v is velocity.

Potential energy is the stored energy in an object due to its position or state, commonly calculated using the formula: $$PE = mgh$$ , where m is mass, g is acceleration due to gravity, and h is height.

Work is done when energy is transferred from one system to another. The amount of work done is equal to the energy transferred.

The unit of power is the Watt (W), which is equivalent to one Joule per second (J/s).

A lightbulb's efficiency indicates how well it converts electrical energy into useful light energy, with higher efficiency meaning less energy wasted as heat.