How much work is required for a 68 kg runner to accelerate from rest to a speed of 6.5 m/s ?

The Kinetic energy will be "1436.5 Joules".

Given values are:

Mass,

Speed,

As we know the formula,

→

By substituting the given values, we get

→                          

→                          

→                          

→                          

Thus the above answer is appropriate.

Learn more about K.E here:

link

-- When he's at rest, his kinetic energy is zero.

-- When he reaches 6.5 m/s, his kinetic energy is . . .

KE = (1/2) (m) (v²)

KE = (34 kg) (42.25 m²/s²)

KE = 1,436.5 Joules

That's the amount of energy that has to come from somewhere, in order to boost him to that speed.

wire in brush may conduct electricity from cell to drill and vice versa electrc shock possible