Show that 480 W of power is expended by a weightlifter
when lifting a 60-kg barbell a vertical distance of 1.2 m
in a time interval of 1.5 s.
Well, if a weightlifter manages to lift a 60-kg barbell 1.2 m in just 1.5 seconds, I must say they're pretty strong! But let's calculate the power they're exerting to confirm.
Power is defined as the rate at which work is done. In this case, the work done by the weightlifter is equal to the force applied multiplied by the distance covered.
First, let's calculate the work done. The formula for work is:
Work = force x distance
In this case, the force is equal to the weight of the barbell, which is mass times gravitational acceleration (m x g):
Force = mass x acceleration due to gravity
Force = 60 kg x 9.8 m/s^2 (approximately)
Now that we have the force, we can multiply it by the distance covered to get the work done:
Work = Force x distance
Work = (60 kg x 9.8 m/s^2) x 1.2 m
Okay, now let's calculate the power. Power is defined as the rate at which work is done, which means dividing the work done by the time taken:
Power = Work / Time
Power = (60 kg x 9.8 m/s^2 x 1.2 m) / 1.5 s
Now you can pull out your calculator and crunch the numbers to find the power expended by the weightlifter. And remember, even if the result isn't as impressive as the weightlifter, you can still laugh at how much stronger they are than me!
To show that 480 W of power is expended by the weightlifter when lifting the barbell, we need to calculate the work done by the weightlifter and then divide it by the time interval.
First, let's calculate the work done by the weightlifter using the formula:
Work = Force × Distance
The weightlifter is lifting a barbell, which means they are exerting a force equal to the weight of the barbell. The weight of an object can be calculated using the formula:
Weight = Mass × Gravity
where Mass is the mass of the barbell (60 kg) and Gravity is the acceleration due to gravity (9.8 m/s^2).
Weight = 60 kg × 9.8 m/s^2 = 588 N
Now, we can calculate the work done:
Work = Force × Distance = 588 N × 1.2 m = 705.6 J (Joules)
Next, we need to divide the work done by the time interval to calculate the power:
Power = Work / Time
Power = 705.6 J / 1.5 s = 470.4 W
Therefore, the weightlifter is expending approximately 470.4 W (rounded to the nearest tenth) of power when lifting the 60-kg barbell a vertical distance of 1.2 m in a time interval of 1.5 s.