Answer :
Final answer:
The problem requires understanding the principle of moments to find the input force needed to lift an object using a lever. Calculations show that the input force required is 315 N.
Explanation:
In this physics problem, we are dealing with the principles of a lever, which is a simple machine. When some firefighters are using a 6 m length of pipe to lift a 63 kg object, the lever's fulcrum is not in the center. To determine how much input force (in newtons) is required, the principle of moments tells us that the force multiplied by its distance from the fulcrum must equal the weight of the object multiplied by its distance from the fulcrum. This is often stated as force times force arm equals weight times weight arm (F × d = W × D).
The weight of the object (W) can be calculated by multiplying its mass (63 kg) by the acceleration due to gravity (9.8 m/s²). With a distance from the fulcrum to the object (D) of 4 m, the equation becomes:
F × (6 m - 4 m) = 63 kg × 9.8 m/s² × 4 m
After calculations, we find that the input force (F) required is 315 N. Therefore, the correct answer is (a) 315 N.
