Explain why a long spanner is preferred to a short on  undoing a tight bolt. 

A long spanner is preferred over a short one for undoing a tight bolt due to the concept of torque. Torque is a measure of the rotational force applied to an object and depends on two factors: the amount of force applied and the distance from the pivot point (in this case, the bolt).

Mathematical Explanation

The torque τ can be calculated using the formula:

τ=F×r

where:

• τ is the torque,
• F is the applied force, and
• r is the distance (lever arm) from the pivot point to where the force is applied.

Since a long spanner has long distance r, less effort is required compared when using a shorter spanner

Dr. Bbosa Science