A motor consumes 36000 joules of electrical energy while performing 7000 joules of useful mechanical work. Calculate: a) The efficiency of the motor b) The energy lost

Mass $m = 500 \text{ kg}$
Acceleration due to gravity $g = 9.81 \text{ m/s}^2$

The load due to the weight of the trolley is $\boxed{\text{4905 N}}$.

Load $W = 4905 \text{ N}$ (from part a)
Effort $E = 1800 \text{ N}$

The mechanical advantage is $\boxed{2.725}$.

Effort distance (length of inclined plane) $L = 10 \text{ m}$
Load distance (vertical height) $h = 2.5 \text{ m}$

The velocity ratio is $\boxed{4}$.

Mechanical Advantage $M.A. = 2.725$ (from part b)
Velocity Ratio $V.R. = 4$ (from part c)

The efficiency of the inclined plane is $\boxed{68.125\%}$.

Effort $E = 1800 \text{ N}$
Effort distance (length of inclined plane) $L = 10 \text{ m}$

The input work is $\boxed{18000 \text{ J}}$.