Assume that global lightning on the Earth constitutes a constant current of 1.00 kA between the ground and an atmospheric layer at potential 260 kV. (a) Find the power of terrestrial lightning.

p= W

(b) For comparison, find the power of sunlight falling on the Earth. Sunlight has an intensity of 1400 W/m2 above the atmosphere. Sunlight falls perpendicularly on the circular projected area that the Earth presents to the Sun.

p= W

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.