Let the observer be 'd' distance away from the thunderstorm and let light take 't' time to reach the observer
Since the speed of sound and light remains constant in a particular medium, we can use
Speed = Distance/Time
For light,
3 x 10^8 = d/t
t = d/(3 x 10^8) -1
For sound,
339 = d/(t + 30) -2
Putting value from 1 in 2.
d = 10^4 m(approx)
The answer is D interferometry
The gravitational force on the car is the force popularly known
as the car's "weight". Its magnitude is
(9.8 m/s²) times (the car's mass, in kilograms) .
The unit of this quantity is [newton] .
Complete Question
The complete question is shown on the first uploaded image
Answer:
The value of
and
Explanation:
Considering the diagram,
Taking moment about the pivot , we have

=> 
Generally given that the bar is at equilibrium then the upward forces is equal to the down ward force
So

=> 
=>
Answer:
The speed of the object just before it hits Earth is 
(A) is correct option.
Explanation:
Given that,
M = mass of earth
R = radius of earth
The potential energy at height above the surface of the earth

The kinetic energy at height above the surface of the earth

The total energy at height above the surface of the earth

....(I)
The total energy at the surface of the earth
....(II)
We need to calculate the speed of the object just before it hits Earth
From equation (I) and (II)

Here, h = R


Hence, The speed of the object just before it hits Earth is
.