A weight lifter is raising a barbell of mass 120kg. He does this in two stages. At the end of the first stage he holds the barbell steady at shoulder height. What upward force is each arm exerting?
presumably, 1/2 of the total, which is 120*9.8N
To calculate the upward force exerted by each arm, we first need to determine the total weight of the barbell. We can do this by multiplying the mass of the barbell by the acceleration due to gravity, which is approximately 9.8 m/s^2.
Weight of the barbell = mass of the barbell × acceleration due to gravity
Weight of the barbell = 120 kg × 9.8 m/s^2
Weight of the barbell = 1176 N
Since the weight lifter is holding the barbell steady at shoulder height, the upward force exerted by each arm must be equal to half of the total weight.
Upward force exerted by each arm = Total weight of the barbell / 2
Upward force exerted by each arm = 1176 N / 2
Upward force exerted by each arm = 588 N
Therefore, each arm is exerting an upward force of 588 Newtons.
To find the upward force exerted by each arm while holding the barbell steady at shoulder height, we need to consider the weight of the barbell and the symmetry of the situation.
Here's how we can approach it:
Step 1: Calculate the total weight of the barbell:
The weight of an object is given by the formula:
Weight = mass × gravitational acceleration
Given that the mass of the barbell is 120 kg, and the standard gravitational acceleration is approximately 9.8 m/s^2, we can calculate the total weight of the barbell:
Weight = 120 kg × 9.8 m/s^2 = 1176 N
Step 2: Divide the total weight between the two arms:
Since the weight is symmetrically distributed, each arm supports an equal share of the weight.
Therefore, the upward force exerted by each arm is half of the total weight:
Upward force exerted by each arm = 1176 N / 2 = 588 N
Thus, each arm is exerting an upward force of 588 Newtons.