The work done on the car is -20 J.
Work done on the car is negative, meaning that the car actually does work on the external system.
<h3>Energy and law of conservation of energy</h3>
- Energy is the ability to do work
- the law of conservation of energy states that the total energy in a system is conserved
From the law of conservation of energy, the initial energy of the car before it moves down the road remains constant or unchanged.
- Initial energy = 100 J
- Initial energy = Final energy - work done on car
- Final Energy = Work done on car + initial energy
80J = Work done on car + 100 J
Work done on car = 80 - 100J
Work done on car = -20 J
Hence, the work done on the car is -20 J
Work done on car is negative.
Since work done on the car is negative, it means that the car actually does work on the external system. Hence, the decrease in the energy of the car.
Learn more about energy and work at: brainly.com/question/13387946
Answer:
surface charge density on each sphere is 
C
Explanation:
given data
radius of smaller sphere = 5 cm
radius of larger sphere is 12 cm
electric field at surface of larger sphere = 660 kV/m = 660 × 1000 v/m
solution
we apply here electric field formula that is express as
E = 
.................1
put here value
660000 = 
Q1 = 1056 × 
and
here field inside a conductor is zero so that electric potential ( V ) is constant
..................2
so Q2 will be
Q2 = 
Q2 = C
The correct answer to this question is false
