Answer:
The surface gravity is inversely proportional to the square of the radius of the planet
Explanation:
The gravity at the surface of a planet is given by:

where
G is the gravitational constant
M is the mass of the planet
R is the radius of the planet
We see from the formula that the surface gravity is inversely proportional to the square of the radius of the planet, R.
At the Earth's surface, the value of the surface gravity is approximately 9.81 m/s^2.
Answer:
Because a person may be pulled in the direction of the moving train. Thereby causing accident
Explanation:
According to Daniel Bernoulli's theorem, he was widely known as a Mathematician. He stated that due to the higher velocity of a moving train, there is higher kinetic energy in terms of volume around it, while the air pressure between the person and the train becomes lower.
As a result, a person near a moving train may be pulled in the direction of the moving train. Thereby causing accidents that may lead to death.
Answer:
The second is correct.
Explanation:
Try with a magnet and experiment. You'll find out
Given:
B =
T
V=
q = 2.5 ×
C
α = 90
To find:
Force = ?
Formula used:
Force on the moving charge is given by,
F = q V B sin α
Where F = force exerted on moving charge
V = velocity of charge
q = charge
α = angle between direction of V and B
Solution:
F = q V B sin α
Where F = force exerted on moving charge
V = velocity of charge
q = charge
α = angle between direction of V and B
F = 
F = 37.5 × 
F = 3.75 Newton
Thus, the force acting on the moving charge is 3.75 Newton.
Explanation:
Below is an attachment containing the solution.