Question

If it took a gardener 20. minutes (1200 s) to finish tilling his garden using 3500 W of power, how much work did he do?

Physics help

Answer 1

`4,200,000 \ "J"=4.2 \ "MJ"`

Explanation:

Well, power is expressed through the equation:

`P=W/t`

where `W` is work done in joules, and `t` is the time in seconds.

Here, we need to solve for work, so we can rearrange the equation into

`W=P*t`

Plugging in the given values, we get

`W=3500 \ "W"*1200 \ "s"`

`=4,200,000 \ "J"`

`=4200 \ "kJ"`

`=4.2 \ "MJ"`

That's actually an unimaginable amount of work done by a human being!

Answer 2

`"4.2 MJ"`

Explanation:

`"Power" = "Work"/"Time"`

`"Work = P × t" = "3500"\ "Joule"/cancel"s" × 1200 cancel"s" = "4200000 Joule"`

In simple,

`"4200000 Joule" = 4.2 × cancel(10^6\ "Joule") × "1 MJ"/(cancel(10^6\ "Joule")) = "4.2 MJ"`