Question

What is the weight in Newton exerted by 10 kg mass on a horizontal stationary surface if the acceleration due to gravity at the place is $10m{s}^{-2}$? How many Newton of force will it exert on a point of support which is undergoing a downward acceleration of $5m{s}^{-2}$? [2 MARKS]

Answer 1

Calculation : 1 Mark each
Step 1 :
Given, mass of the body, $m=10kg$ and acceleration, $a=10m{s}^{-2}$
Weight = Force exerted by the earth on the body$=ma=10\times 10=100N.$

Step 2 :
Given, net acceleration, $a=10-5=5m{s}^{-2}$ downwards and mass of body $m=10kg$.
Thus, force exerted, $F=ma=10\times 5=50N$.