Question

An applied force of 20 N accelerates a block across a level,frictionless surface from rest to a velocity of 8.0 m/s in a time of 2.5 s. Calculate the work done by this force.

Answer 1

workdone = force × distance

Step-by-step explanation:

let's find the acceleration

`v = u + at \\ 8 = 0 * a * 2.5 \\ \alpha = 3.2m {s}^( - 2)`

then distance

`{v}^(2) = {u}^(2) + 2as \\ {8}^(2) = 2 * 3.2 * s \\ \\ s = 10m`

w = f ×d

= 20 × 10

= 200J