Vi = vf + ( a.t)
0 m/s (rest) = 80 m/s + (a.20s.-1)
a.20.-1= -80, we check if this is true; = 0 m/s= 80 + -80 = 0 ITS TRUE.
so a.20.-1= -80, a= 80/20 , Answers a= 4 m/s
They were published in 1542.
Convection. It is the transfer of heat by the circulation and movement of the molecules that come from liquid or gas.
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
