Question

Find the weight of a 15 kg rock. Acceleration due to gravity is 9.8 m/s2.

Answer 1

Weight of an object is defined as the attraction force of Earth on  the objects due to gravitation

So the formula to find the weight is given by

$W = mg$

here

m = mass of object = 15 kg

g = acceleration due to gravity = 9.8 m/s^2

now using the formula of weight above

$W = 15 * 9.8$

$W = 147 N$

so the weight of the rock will be 147 N