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