Question

What force should be applied on a 5 kg body so
that it has a downward acceleration of 4 m/s??
a) 69 N upwards b) 69 N downwards
c) 29 N upwards d) 29 N downwards​

Answer 1

F=ma

=5×4×5/18

=5×20/18

=100/18

=5.55N

also your question is wrong as acceleration is always in m/s^2

Answer 2

Answer:

Here they ask the downward accilaration. So here

net force needed will be m(g-a)

that is 5×(9.8-4) =29N

But for downward accilaration the direction of force is not downward. That is the Missconcept. Here the force is upward. So option C is correct