Question

problem 3:
define potential energy and explain in words. using this definition find the potential energy expression due to gravity if the potential energy is 0 at position 0. if you lift a 30 kg weight a height of 0.7 m, find its potential energy.

Explanation:

Step1: Define potential energy

Potential energy is the energy stored in an object due to its position or configuration.

Step2: Derive gravitational potential energy formula

Work done \(W = F\times d\). Force \(F = mg\) (where \(m\) is mass and \(g\) is acceleration due to gravity, \(g = 9.8\ m/s^{2}\)), distance \(d=h\) (height). So \(U = mgh\) (since potential energy is equal to work done against gravity and \(U(0)=0\))

Step3: Calculate potential energy for given values

Given \(m = 30\ kg\), \(h=0.7\ m\), \(g = 9.8\ m/s^{2}\). Substitute into \(U=mgh\): \(U=30\times9.8\times0.7\)

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Answer:

The potential energy of the \(30\ kg\) weight lifted to a height of \(0.7\ m\) is \(205.8\ J\)