# Can someone help me with a few physics question ? with steps please !!

## Find the acceleration produced by a total force of 115 N on a mass of 31.4 kg. 2.Find the mass of an automobile that weighs 12,052 N.

Feb 10, 2018

1 . Force is defined as rate of change in momentum, i.e $F = \frac{\mathrm{dP}}{\mathrm{dt}} = m \frac{\mathrm{dv}}{\mathrm{dt}}$ (for $m$ is constant)

Now, $\frac{\mathrm{dv}}{\mathrm{dt}}$=rate of change in velocity=acceleration=$a$

So,$F = m a$

Given,$F = 115 N , m = 31.4 K g$

So,acceleration = $\frac{115}{31.4} = 3.67 \frac{m}{s} ^ 2$

2 . Weight of an object on the Earth means,the gravitational force with which the object is being pulled towards the earth.

So, for a particle of mass $m$ it can be written as, $F = \frac{G \left(M m\right)}{r} ^ 2$ (where, $M$ is the mass of the earth,$r$ is the radius of earth)

or,we can write as, $F = m g$ (where, $g = \frac{G M}{r} ^ 2$=acceleration due to gravity)

Given, $F = 12052 N$ and we know $g = 9.81 \frac{m}{s} ^ 2$

So, its mass will be = $\frac{12052}{9.81} = 1228.54 K g$