Question

at point w the cart has a total of 100 joules of energy. at point x, the cart has 20 joules of potential energy. how much kinetic energy does it have? (assume that no energy was lost due to friction) 20 joules 100 joules 80 joules 120 joules

Explanation:

Step1: Apply the law of conservation of energy

The total mechanical energy \(E\) is conserved. At point \(W\), \(E = 100\) J (total energy). At point \(X\), the total energy \(E\) is the sum of potential energy \(U\) and kinetic energy \(K\), i.e., \(E=U + K\).

Step2: Substitute the known values

We know that \(E = 100\) J and \(U=20\) J. Using the formula \(K=E - U\).
Substitute \(E = 100\) J and \(U = 20\) J into the formula: \(K=100 - 20\).

Answer:

\(80\) Joules