And no force on earth could cause it to disclose the key.

The force causing the change need not be very powerful.

At least to me they seem crazy because I have no idea where the forces causing all that come from.

When he hit the ground, the force of the fall caused his arms to spring out sideways.

And what force had caused the knife to reveal its true nature?

The reality is that it takes violent forces to cause these injuries.

Question: what force will cause your tube to turn over at the top of it's arc?

What force causes a 3-pole motor to spin one way and not the other?

New productive forces will cause conflict in the current mode of production.

If a force only causes the object to change direction, there is no transfer of energy.