a weightlifter raises a 70 kg barbell from the floor to a height of 2.2m in 1.2s. What was his average power output during the lift?

the unit for work should be Joule,nut newton..

the unit for work should be Joule,not newton..

Power=work/time

Work=force*distance
w=(9.81m/s*70kg)*2.2m
w=1510.74 Newton

P=1510.74N/1.2s
P=1259.95 watts or 1.26 Kilowatts

To calculate the weightlifter's average power output during the lift, we need to use the formula:

Average Power (P) = Work (W) / Time (t)

First, let's calculate the work done by the weightlifter. The work done is equal to the force applied multiplied by the distance moved in the direction of the force.

In this case, the force applied is equal to the weight of the barbell, which can be calculated using the formula:

Weight (W) = Mass (m) * Gravitational Acceleration (g)

Given that the mass is 70 kg and the gravitational acceleration is approximately 9.8 m/s^2:

Weight (W) = 70 kg * 9.8 m/s^2
= 686 N

Next, we need to calculate the distance moved, which is equal to the height raised:

Distance (d) = 2.2 m

Now we can calculate the work done:

Work (W) = Force (W) * Distance (d)
= 686 N * 2.2 m
= 1509.2 Joules (J)

Finally, we can calculate the average power:

Average Power (P) = Work (W) / Time (t)
= 1509.2 J / 1.2 s
= 1257 Watts (W)

Therefore, the weightlifter's average power output during the lift is approximately 1257 Watts.