To figure out the energy in a moving object, we focus on two main types of energy: kinetic energy and potential energy. Let’s make this simple.

Kinetic Energy

Kinetic energy is the energy an object has when it’s moving. We can find it using this formula:

[ KE = \frac{1}{2} mv^2 ]

In this formula:

• KE stands for kinetic energy (measured in joules),
• m represents the mass of the object (measured in kilograms),
• v is the speed of the object (measured in meters per second).

Example:

Let’s say a car weighs 1,000 kg and is going 20 m/s. We can calculate its kinetic energy like this:

[ KE = \frac{1}{2} (1000 kg)(20 m/s)^2 = \frac{1}{2} (1000)(400) = 200,000 J ]

So, this car has 200,000 joules of kinetic energy.

Potential Energy

Now, when an object is up high, it has gravitational potential energy. We can calculate this using the formula:

[ PE = mgh ]

In this case:

• PE is the potential energy (also in joules),
• m is the mass (in kilograms),
• g is the pull of gravity (which is about 9.81 m/s² on Earth),
• h is how high the object is above the ground (in meters).

Example:

If that same car is parked on a hill that’s 10 meters high, we can find its potential energy like this:

[ PE = (1000 kg)(9.81 m/s^2)(10 m) = 98,100 J ]

Energy Conservation

In many situations, energy can switch between kinetic and potential but stays the same overall (in a closed system). For example, when the car goes down the hill, its potential energy turns into kinetic energy.

Conclusion

Knowing how to calculate kinetic and potential energy helps you solve physics problems and understand energy transfer. Try practicing these calculations with different examples to get a better idea of energy in motion!