If the rope pulling on the leg exerts a 120-N force on it, how massive should be the block hanging from the rope that passes over the pulley?
To determine the mass of the block hanging from the rope, we need to use Newton's second law of motion, which states that force equals mass multiplied by acceleration (F = m × a).
In this case, the force exerted on the leg is given as 120 N. However, to find the mass of the block, we need to consider the acceleration caused by this force.
Now, let's break down the problem:
1. First, we need to identify the forces acting on the block. Since the rope is pulling the leg, the force exerted by the rope will be equal to the force exerted by the leg on the rope, which is 120 N.
2. Assuming the rope is ideal and without friction, the force acting on the block is also 120 N.
3. We know that the force acting on the block is equal to the weight of the block (force = mass × acceleration due to gravity). Here, the acceleration due to gravity is approximately 9.8 m/s².
4. Now, we can calculate the mass of the block by rearranging the formula: mass = force / acceleration.
mass = 120 N / 9.8 m/s² ≈ 12.24 kg
Therefore, the block hanging from the rope should have a mass of approximately 12.24 kg in order for the rope pulling on the leg to exert a 120 N force on it.