What power is expended by a weightlifter when lifting a 56-kg barbell a vertical distance of 1.0 m in a time interval of 1.4 s .
Express your answer to two significant figures and include the appropriate units.
56 kg * 9.8 m/s^2 * 1.0 m / 1.4 s = ? Watts
Well, if you want to compute the power exerted by a weightlifter, you need to know the formula for power, which is power = work/time. In this case, the work done is the force applied by the weightlifter times the distance over which the force is applied.
To find the force, we can use the equation F = ma, where F is the force, m is the mass of the barbell, and a is the acceleration. The acceleration of the barbell can be calculated using the equation a = Δv/Δt, where Δv is the change in velocity and Δt is the time interval. In this case, since the barbell is lifted vertically, Δv is equal to 0 because the barbell starts and ends with a velocity of 0. So the acceleration a = 0/Δt = 0.
Since the acceleration is 0, the force required to lift the barbell is equal to the weight of the barbell, which is F = mg = (56 kg)(9.8 m/s^2) = 549.6 N.
Now that we have the force and the distance over which it is applied, we can calculate the work done, which is W = Fd = (549.6 N)(1.0 m) = 549.6 Joules.
Finally, we can calculate the power by dividing the work done by the time interval: power = work/time = 549.6 J / 1.4 s = 392.6 Watts.
So, the power expended by the weightlifter is approximately 392.6 Watts. But I must ask, have you ever considered becoming a weightlifter? They really know how to lift the bar!
To calculate the power (P) expended by the weightlifter when lifting the barbell, we can use the formula:
P = (work done) / (time)
First, we need to calculate the work done (W). The work done is equal to the force (F) applied multiplied by the distance (d) moved. In this case, the force is equal to the weight (mg) of the barbell, where m is the mass of the barbell (56 kg) and g is the acceleration due to gravity (approximately 9.8 m/s^2).
So, the work done is given by:
W = F * d = (mg) * d
W = (56 kg * 9.8 m/s^2) * 1.0 m
W = 548.8 N * m
Now that we have the work done, we can calculate the power by dividing the work done by the time interval (t).
P = W / t = 548.8 N * m / 1.4 s
P = 392.0 W
Rounded to two significant figures, the power expended by the weightlifter is 390 W.
To find the power expended by the weightlifter, we need to use the formula for power:
Power = work / time
First, we need to find the work done by the weightlifter. The work done is equal to the force applied multiplied by the distance over which the force is applied. In this case, the force applied by the weightlifter is equal to the weight of the barbell, which can be calculated using the gravitational force equation:
Force = mass * acceleration due to gravity
The acceleration due to gravity is approximately 9.8 m/s².
Force = 56 kg * 9.8 m/s² = 549.6 N
The distance over which the force is applied is given as 1.0 m.
Now we can calculate the work done:
Work = force * distance = 549.6 N * 1.0 m = 549.6 J
Finally, we can calculate the power:
Power = Work / Time = 549.6 J / 1.4 s = 392.57 W
Rounding to two significant figures, the power expended by the weightlifter is approximately 390 W.
Therefore, the power expended by the weightlifter when lifting a 56-kg barbell a vertical distance of 1.0 m in a time interval of 1.4 s is approximately 390 W (watts).