Question

(a) What is the force of gravity between two 1160 kg cars separated by a distance of 35 m on an interstate highway? (b) How does this force compare with the weight of a car?

Answer 1

Explanation:

(a) Mass of the cars, m₁ = m₂ = 1160 kg

Distance between cars, d = 35 m

The gravitational force between two cars is given by :

$F=G\dfrac{m_1m_2}{d^2}$

$F=6.67\times 10^{-11}\times \dfrac{(1160)^2}{(35)^2}$

$F=7.32\times 10^{-8}\ N$

So, the force of gravity between the cars is $7.32\times 10^{-8}\ N$.

(b)The weight of a car is given by :

$W=mg$

$W=1160\times 9.8$

W = 11368 N

On comparing,

$\dfrac{W}{F}=\dfrac{11368}{7.32\times 10^{-8}}$

$\dfrac{W}{F}=1.55\times 10^{11}$

$W=1.55\times 10^{11}\times F$

So, the weight of the car is $1.55\times 10^{11}$ times the force of gravitation between the cars.