The radar device determines the vehicle's instantaneous speed.
I would argue that the purpose of the device is not to determine
whether individuals are driving safely. They only determine whether
individuals are driving within legal speed limits. There's much more
to 'safe' driving than that, but the radar gun can't detect it.
(a) 
The change in energy of the transferred charge is given by:

where
q is the charge transferred
is the potential difference between the ground and the clouds
Here we have


So the change in energy is

(b) 7921 m/s
If the energy released is used to accelerate the car from rest, than its final kinetic energy would be

where
m = 950 kg is the mass of the car
v is the final speed of the car
Here the energy given to the car is

Therefore by re-arranging the equation, we find the final speed of the car:

Answer: d₂ = 170 mGya
Explanation:
the relationship between absonbed 'd' and exposure 'E' is given as;
D(Gv) = F . x (AS/xB)
F is a conversion coefficient depending on medium
so we can simply write
d₁/d₂ = x₁/x₂
Given that;
our x₁ = 60 mAs, x₂ = 120 mAs, d₁ = 85 mGya, d₂ = ?
from the given formula,
d₂ = (x₂d₁ / x₁)
now we substitute
d₂ = (120 × 85) / 60
d₂ = 170 mGya
∴ if 120 mAa is used, the new exposure will be 170 mGya
I would say The answer is false