What is the total work done on the barbell when a weightlifter brings a 400-N barbell upward from his shoulders to a point 50 cm higher at a steady speed?
The total work done on the barbell by the weightlifter is 200 Joules, assuming that the barbell is lifted at a steady speed.
Calculation of Work Done
How do we calculate work done?
The work done on an object is calculated as:
W = Fd cos(θ)
Where:
W is the work done,
F is the force applied,
d is the distance over which the force is applied,
and θ is the angle between the direction of the force and the direction of motion.
In the case of the weightlifter lifting the barbell, the barbell is being lifted straight up. Thus, the angle θ is 0 degrees (the force and motion are in the same direction), and cos(0) = 1.
Substituting the given values into the formula:
W = (400 N)(0.5 m)(cos 0)
W = 200 J
Therefore, the total work done on the barbell by the weightlifter in lifting it 50 cm higher is 200 Joules.
For additional exercises on calculating work done, you can explore more examples on platforms like educational websites or forums dedicated to physics.