In a certain lightning flash, the potential difference between a cloud and the ground is! 1.0 x 109 v and the quantity of charge transferred is 30 c. (a) what is the change in energy of the transferred charge? (b) if all the energy released by the transfer could be used to accelerate a 1000 kg automobile from rest, what would be the automobiles final speed?

a) 3.0 x 10¹⁰ J

b) 7.75 x 10³ m/s

Explanation:

a)

ΔV = potential difference between cloud and the ground = 1.0 x 10⁹ Volts

Q = Amount of charge transferred = 30 C

ΔU = Change in energy transferred

Change in energy transferred is given as

ΔU = Q ΔV

ΔU = (30) (1.0 x 10⁹)

ΔU = 3.0 x 10¹⁰ J

b)

v₀ = initial speed of the automobile = 0 m/s

v = final speed of the automobile = ?

m = mass of automobile = 1000 kg

Using conservation of energy

ΔU = (0.5) m (v² - v₀²)

3.0 x 10¹⁰ = (0.5) (1000) (v² - 0²)

v = 7.75 x 10³ m/s

object 2 because all the other ones are wrong

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.