why does the load reaches 50 meters from the ground will the correct position of the PE and KE that the problem isa crane lifted a 1000 kg load to a height of 50 meters from the ground. at which position are the PE and KE of the load equal

I don't understand your question.

at 50 m

To find the position at which the potential energy (PE) and kinetic energy (KE) of the load are equal, we need to understand the concepts of PE and KE and how they relate to each other.

Potential energy (PE) is the energy possessed by an object due to its position or state. In this case, the load gains potential energy as it is lifted higher off the ground. The formula to calculate the potential energy is:

PE = m * g * h

Where m represents the mass of the load, g represents the acceleration due to gravity (approximately 9.8 m/s²), and h represents the height or distance above the reference point (in this case, the ground).

Kinetic energy (KE), on the other hand, is the energy possessed by an object due to its motion. The formula to calculate kinetic energy is:

KE = (1/2) * m * v²

Where m represents the mass of the load, and v represents the velocity or speed of the load.

To find the position at which PE and KE are equal, we can set up an equation by equating the formulas for PE and KE and solving for the height (h):

PE = KE
m * g * h = (1/2) * m * v²

The mass of the load, m, cancels out, simplifying the equation to:

g * h = (1/2) * v²

We can further simplify by substituting the value of g as 9.8 m/s²:

9.8 * h = (1/2) * v²

Since we are given the height, h, as 50 meters, we can substitute this value into the equation:

9.8 * 50 = (1/2) * v²
490 = (1/2) * v²

To solve for v, we can multiply both sides of the equation by 2 and then take the square root of both sides:

980 = v²
v = √980
v ≈ 31.3 m/s

Therefore, at a height of 50 meters, the load will have equal potential energy (PE) and kinetic energy (KE) when it is moving with a velocity of approximately 31.3 m/s.