" 478 watts " means 478 joules per second.
In 14 seconds, the total work or energy is (14 x 478) = <em>6,692 joules</em>
The electric power used by the car battery is given by
where
V is the voltage of the battety
I is the current
P is the electric power.
For the battery in our problem, the voltage is V=12.0 V while the current intensity is I=0.5 A, so the power used by the battery is
Actually the question is not clear. The Benefit of lifting using lever is that you can apply force in a convenient direction and you can use very less force to lift object by balancing the torque due to object.For example you want to lift a mass of 4N with a force 2N you can use a class 2 lever and maintain the ratio between the distances of the body and the point of application of force from the fulcrum to be 1:2.In any case balance the torque to get the required force.
7(a) transpiration is faster in warmer dry air
(b)(I)xylem
(ii) 1. They are stacked end-to-end
2. Consists of dead cells