a weightlifter raises a 200-kg barbell with an acceleration of 3 m/s. How much force does the weightlifter use to raise the barb?

400kg

IT would take the force of 400 N

400

To calculate the amount of force the weightlifter uses to raise the barbell, we can use Newton's second law of motion, which states that force (F) is equal to mass (m) multiplied by acceleration (a).

The given mass of the barbell is 200 kg, and the acceleration is 3 m/s². Plugging these values into the equation, we have:

F = m * a
F = 200 kg * 3 m/s²
F = 600 N

Therefore, the weightlifter uses a force of 600 Newtons to raise the barbell.

A weightlifter raises a 200-kg barbell through a height of 2 m in 2.2 s. The average power he develops during the lift is

40000 kg

To maintain the weight at the same place, the force required is mg.

To accelerate upwards at acceleration a=3m/s², he/she must apply an additional force of ma.
So the total force is
m(g+a) N
where
m=mass of weight
g=acceleration due to gravity
a=acceleration upwards.