Question

An object having a mass of 2.0 kilograms falls from a height of 15 meters. What is its kinetic energy when it hits the ground? A. 30 joules B. 2.2 × 102 joules C. 2.9 × 102 joules D. 3.3 × 102 joules

Answer 1

option c

Step-by-step explanation:

Answer 2

Option C : 290 J

Step-by-step explanation:

We can use conservation of energy to estimate the kinetic energy when the object hits the ground:

When the object is at its initial height of 15 meters, it velocity is zero (falls from this position), therefore the total energy it possesses is due to potential energy given by the expression:

`mgh=2*9.8*15 = 294` Joules

At the moment the object hits the ground from its free fall, its potential energy is zero, while its kinetic energy must equal the rest. So at that moment the object's kinetic energy must be 294 Joules.