Answer:
The efficiency of the engine is 40 %
Explanation:
Given;
input energy, = 2500 J
output energy, = 1000 J
The efficiency of the engine is given as;
Efficiency = output energy / input energy
Efficiency = 1000 / 2500
Efficiency = 0.4
Efficiency(%) = 0.4 x 100%
Efficiency = 40 %
Therefore, the efficiency of the engine is 40 %
In water, it's drag. Exactly the same as air resistance
only hundreds of times greater.
Static charge is occurring
The electrostatic force between two charged objects is given by

where
k is the Coulomb's constant
q1 is the charge of the first object
q2 is the charge of the second object
r is the separation between the two objects
In our problem:



So if we plug these numbers into the equation, we can find the electrostatic force between the two objects:
Light intensity and distance is
interrelated. When the distance changes, the intensity of light changes. This relationship
is called inverse-square relationship. The inverse-square relationship refers
to the fact that when distance changes, light intensity also changes: inverse
because when distance decreases, light density increases and when distance
increases, the latter decreases; square refers to the fact that light intensity
and distance is not a one-to-one relationship.