Question

In a loading van the driver pushed a 15kg crate for 5 meters up the ramp. She had to push with a force of 132N and the vertical height gained was 1.3m. What was the efficiency of pushing this crate up the ramp onto the back of the van?

Answer 1

$F = 132N$

$s = 5m$

$m= 15kg$

$h= 1.3m$

$g=9.8\frac{m}{s^2}$

$\eta= \frac{W_{output}}{W_{input}}*100 \%$

$W_{output }= mgh = 15*9.8*1.3= 191.1J$

$W_{input}=Fs=132*5=660J$

$\eta= \frac{191.1}{660}*100\%\approx 29\%$

$\text{Answer: }\eta = 29\%$