An object has a mass of 6 kg. The object's kinetic energy uniformly changes from 96 KJ to  108 KJ over t in [0, 3 s]. What is the average speed of the object?

Feb 8, 2017

5.83 m/s

Explanation:

Kinetic energy = $\left(\frac{1}{2}\right) \cdot M \cdot {V}^{2}$ The average speed will be the average of the initial and final velocities.
1 Joule is equivalent to $1 k g \cdot {\left(\frac{m}{s}\right)}^{2.}$
${\left({V}_{1}\right)}^{2} = \left(\frac{96 \cdot 2}{6}\right) \mathmr{and} {\left({V}_{2}\right)}^{2} = \left(\frac{108 \cdot 2}{6}\right)$
${\left({V}_{1}\right)}^{2} = 32 \mathmr{and} {\left({V}_{2}\right)}^{2} = 36$
${V}_{1} = 5.66 \mathmr{and} {V}_{2} = 6$ ;
The average is (5.66 + 6)/2 = 5.83 m/s
The duration of the acceleration is irrelevant.

Mar 10, 2017

Similar question answered here.

The discussion reveals that

the change in velocity in each second interval is not constant. As such, acceleration is not constant. Therefore, the known expressions for linear motion for constant acceleration can not be applied to find a solution.