Question

a 2.00 kg ball is thrown upward at some unknown angle from the top of a 20.0 m high building. if the initial magnitude of the velocity of the ball is 20.0 m/s. what is the value of total energy? a 792 j b 487 j c 290 j d 593 j

Explanation:

Step1: Calculate kinetic energy

Kinetic energy formula: \(K = \frac{1}{2}mv^{2}\). Given \(m = 2.00\space kg\), \(v=20.0\space m/s\).
\(K=\frac{1}{2}\times2.00\times(20.0)^{2}= 400\space J\)

Step2: Calculate potential energy

Potential energy formula: \(U = mgh\). Given \(m = 2.00\space kg\), \(g = 9.8\space m/s^{2}\), \(h = 20.0\space m\).
\(U=2.00\times9.8\times20.0 = 392\space J\)

Step3: Calculate total energy

Total energy \(E=K + U\)
\(E=400+392=792\space J\)

Answer:

A. 792 J