Question

a 1,100 kg car is traveling at 20 m/s as it begins going down a 40 m hill. what is its total mechanical energy? (1 point) 220,000 j 211,200 j 431,200 j 651,200 j

Explanation:

Step1: Calculate kinetic energy

The formula for kinetic energy \(K = \frac{1}{2}mv^{2}\). Given \(m = 1100\space kg\) and \(v=20\space m/s\), then \(K=\frac{1}{2}\times1100\times20^{2}= 220000\space J\)

Step2: Calculate potential energy

The formula for potential energy \(U = mgh\). Given \(m = 1100\space kg\), \(g = 9.8\space m/s^{2}\), and \(h = 40\space m\), then \(U=1100\times9.8\times40=431200\space J\)

Step3: Calculate total mechanical energy

The total mechanical energy \(E=K + U\). Substitute \(K = 220000\space J\) and \(U = 431200\space J\) into the formula, \(E=220000+431200 = 651200\space J\)

Answer:

651,200 J