Question

a man carries a 10 kg sack of groceries in his arms with a force of 50 n as he walks forward a distance of 10 m how much work has he done

Answer 1

500 Joules. 

To find this answer you need an equation. The equation is fairly simple. W=F*D  "Work equals Force times Distance"

There are 50 Newtons over 10 meters as you said. So...

500J = 50N * 10m

Answer 2

Explanation :

It is given that :

Mass of man, m = 10 kg

Force, F = 50 N

Distance, d = 10 m

We know that, the work done depends on the following factors :

$W = Fd cos\theta$

where,

$\theta$ is the angle between force and the displacement.

In this case, a man carries a 10 kg sack of groceries in his arms with a force of 50 N as he walks forward a distance of 10 m. His weight mg will act downward and the displacement is forward.

So, the angle between force and displacement is 90.

$W =50\times 10\times cos(90)$

This implies, work done W = 0

Hence, this is the required solution.