Answer:
The energy that the truck lose to air resistance per hour is 87.47MJ
Explanation:
To solve this exercise it is necessary to compile the concepts of kinetic energy because of the drag force given in aerodynamic bodies. According to the theory we know that the drag force is defined by
Our values are:
Replacing,
We need calculate now the energy lost through a time T, then,
But we know that d is equal to
Where
v is the velocity and t the time. However the time is given in seconds but for this problem we need the time in hours, so,
(per hour)
Therefore the energy that the truck lose to air resistance per hour is 87.47MJ
(a) 120.8 m/s^2
The gravitational acceleration at a generic distance r from the centre of the planet is
where
G is the gravitational constant
M' is the mass enclosed by the spherical surface of radius r
r is the distance from the centre
For this part of the problem,
so the mass enclosed is just the mass of the core:
So the gravitational acceleration is
(b) 67.1 m/s^2
In this part of the problem,
and the mass enclosed here is the sum of the mass of the core and the mass of the shell, so
so the gravitational acceleration is
Answer:
Explanation:
According to newton's law , force between mass m₁ and m₂ at distance x is given by the following expression
F = G m₁m₂ / x²
differentiating F with respect to x , we have
dF / d x = ₋2G m₁m₂ / x³ .
Rate of reduction of force ∝ 1 / x³
