Answer:

Explanation:
The strength of the gravitational field at the surface of a planet is given by
(1)
where
G is the gravitational constant
M is the mass of the planet
R is the radius of the planet
For the Earth:

For the unknown planet,

Substituting into the eq.(1), we find the gravitational acceleration of planet X relative to that of the Earth:

And substituting g = 9.8 m/s^2,

Answer:
1.5 m
Explanation:
H = actual height of the superhero = ?
H₀ = height of the superhero as observed = 1.73 m
v = speed of the superhero = 0.50 c
Using the equation

Inserting the values

H = 1.5 m
Choice ' C ' is a true statement.
The other choices aren't.
Answer: 
Explanation:
Given
Radioactive material is found to decrease 40% of its original value in 
Sample at any time is given by

where, 
Put values

Taking natural logarithm both side
