Answer:
Distance between centre of Earth and centre of Moon is 3.85 x 10⁸ m
Explanation:
The attractive force experienced by two mass objects is known as Gravitational force.
The gravitational force is determine by the relation:
....(1)
According to the problem,
Mass of Moon, m₁ = 7.35 x 10²² kg
Mass of Earth, m₂ = 5.97 x 10²⁴ kg
Gravitational force experienced by them, F = 1.98 x 10²⁰ N
Universal gravitational constant, G = 6.67 x 10⁻¹¹ Nm²kg⁻²
Substitute these values in equation (1).



d = 3.85 x 10⁸ m
<span>79.75m/s .................................</span>
the answer of this question is helium
Answer:
Explanation:
Given
length of window 
time Frame for which rock can be seen is 
Suppose h is height above which rock is dropped
Time taken to cover 
so using equation of motion

where y=displacement
u=initial velocity
a=acceleration
t=time
time taken to travel h is

Subtract 1 and 2 we get


and from equation 
so 

and 
so 



substitute the value of
in equation 2

