How do you calculate work done against gravity?

Work done against gravity is calculated by multiplying the force (weight) by the distance moved and the cosine of the angle.

In more detail, work done against gravity, or any force, is given by the equation W = Fd cos θ. Here, W represents the work done, F is the force applied, d is the distance over which the force is applied, and θ is the angle between the force and the direction of motion.

When we talk about work done against gravity, the force we're considering is the weight of the object being moved. Weight is the force exerted on an object due to gravity and is calculated by multiplying the mass of the object (m) by the acceleration due to gravity (g). Therefore, the force F in our equation becomes mg.

The angle θ in this context is the angle between the direction of the force (which is downwards for gravity) and the direction of motion. If the object is being lifted straight up, the angle is 0 degrees and cos θ is 1. If the object is being moved horizontally, the angle is 90 degrees and cos θ is 0, meaning no work is done against gravity.

So, if you're lifting an object straight up, the work done against gravity is simply the weight of the object times the height it's lifted (W = mgh). If the object is being moved at an angle, you'll need to take that into account by multiplying by the cosine of that angle.

IB Physics Tutor Summary: Work done against gravity is calculated by the formula W = mgh, where W is the work done, m is the mass, g is the gravity, and h is the height lifted. If the object moves at an angle, include the cosine of the angle in the calculation. Simply, it's the object's weight times the height moved, adjusted for any angle.