how much torque do you exert if you push perpendicularly on a door with a force of 30 N at a distance of 0.85 m from its hinges
Use the definition of torque. It is the product of the force and the lever arm, when the two are perpendicular, as they are here.
To calculate the torque exerted on a door, you need to know the force applied and the distance from the point of rotation (hinges) to the line of action of the force. The formula to calculate torque is:
Torque = force × distance
Now, let's plug in the given values:
Force = 30 N
Distance = 0.85 m
Torque = 30 N × 0.85 m
= 25.5 N·m (Newton-meters)
Therefore, you exert a torque of 25.5 Newton-meters on the door when pushing perpendicularly with a force of 30 N at a distance of 0.85 m from its hinges.