Question

A raindrop has a mass of 7.7 × 10-7 kg and is falling near the surface of the earth. Calculate the magnitude of the gravitational force exerted (a) on the raindrop by the earth and (b) on the earth by the raindrop.(a)Fraindrop= _________________ units ________(b)Fearth= _________________ units_____________

Answer 1

a) Fraindrop

`F=7.546\cdot10^(-6)N`

(b) Fearth

`F=-7.546\cdot10^(-6)N`

Explanation:

(a)

We calculate the force, multiplying the value of the mass by gravity, just like this:

`\begin{gathered} F=m\cdot a \\ F=7.7\cdot10^(-7)\cdot9.8 \\ F=7.546\cdot10^(-6)N \end{gathered}`

(b)

by newton's 3rd law they are are equal and opposite so:

`F=-7.546\cdot10^(-6)N`