The current is defined as the amount of charge transferred through a certain point in a certain time interval:

where
I is the current
Q is the charge

is the time interval
For the lightning bolt in our problem, Q=6.0 C and

, so the average current during the event is
Answer:

(we need the mass of the astronaut A)
Explanation:
We can solve this by using the conservation law of the linear momentum P. First we need to represent every mass as a particle. Also we can simplify this system of particles by considering only the astronaut A with an initial speed
of 0 m/s and a mass
and the IMAX camera with an initial speed
of 7.5 m/s and a mass
of 15.0 kg.
The law of conservation says that the linear momentum P (the sum of the products between all masses and its speeds) is constant in time. The equation for this is:

By the law of conservation we know that
For
(final linear momentum) we need to treat the collision as a plastic one (the two particles stick together after the encounter).
So:


Answer:
The value of R is
.
(B) is correct option.
Explanation:
Given that,
In analyzing distances by apply ing the physics of gravitational forces, an astronomer has obtained the expression

We need to calculate this for value of R


So, The nearest option of the value of R is 
Hence, The value of R is
.