A rusted bolt requires 30 J of torque to be loosened. If only 40 N of force is applied to a wrench with which it makes a 90° angle, how long is wrench?

To solve this problem, we need to use the concept of torque, which is the rotational equivalent of force. Torque can be calculated by multiplying the force applied perpendicular to the lever arm by the length of the lever arm.

In this case, the torque required to loosen the rusted bolt is given as 30 J (Joules). The force applied is 40 N (Newtons), and it makes a 90° angle with the wrench.

To find the length of the wrench, we can rearrange the formula for torque:

Torque = Force x Lever Arm

Substituting the given values, we have:

30 J = 40 N x Lever Arm

Now, rearranging the equation to solve for the lever arm, we divide both sides by 40 N:

Lever Arm = 30 J / 40 N

Simplifying further, we have:

Lever Arm = 0.75 m

Therefore, the length of the wrench is 0.75 meters.