Question

Suppose a rock is hoisted up with a rope. The rock experiences 10 N of tension force upward and 10 N of gravitational force downward. The total net force on the rock is 20 N. True False

Answer 1

False. Since the forces are pulling in equal and opposite directions, the net force is 0.

Answer 2

10N of tension upwards is positive

10N of gravitational Force downwards is negative

Net Force = The sum of all forces

$F_{net} = F_{tension} + F_{gravity}$

$F_{net} = 10N + (-10N) = 0$

So the answer is false.

Extra Info: If the net force was 20N there would be a tensional force of 30N moving the rock upwards.

30N - 10N = 20N