The mass of a planet determines the acceleration due to gravity on it. This is according to Newton's Law of Gravitation, which basically states that the more mass a body has, the greater the force of attraction it exerts on other bodies with mass near it.
The gravitational force is:
F = GMm/r², where G is a constant, r is the distance between large mass M and small mass m.
Considering the fact that acceleration is force per unit mass, if we divide gravitational force by the small mass (to get force per unit mass), we see the dependence mathematically:
a = GM/r²
Answer:
a)
, b) 
Explanation:
a) The Hooke's law states that spring force is directly proportional to change in length. That is to say:

In this case, the force is equal to the weight of the object:



The spring constant is:



b) The length of the spring is:




Answer:
x=0.154kg
Explanation:
(x*L)+(0.5kg*4200*50)+(x*4200*(-50)=0
(x*333 000J/kg*c)+(0.5kg*4200J/kg*C*(-40C))+(x*4200J/kg*C*50C)=0
Answer:
refractive index of the unknown material is 1.33.
Explanation:
μ₁ = 1.21
incidence angle (i) = 41.9°
refraction angle (r) = 37.3°
Let us assume μ be the refractive index of the unknown material
according to snell's law of refraction.
μ₁ sin i = μ₂ sin r
1.21 × sin 41.9° = μ × sin 37.3°
μ = 1.33
hence the refractive index of the unknown material comes out top be 1.33