A crane slowly lifts a cement slab weighing 2,500 N to a height of 12 m. The slab is accidentally dropped. What is its KE as it hits the ground?
it must be 2500*12 Joules
idk the answer Soooooo!!!!!!!!!!! tell me
It's 30,000J
To calculate the kinetic energy (KE) of an object, we need two pieces of information: the mass of the object and its velocity. Unfortunately, we do not have the velocity of the slab, only its weight. However, we can still calculate the potential energy (PE) of the slab when it is at its highest point, and then convert that to its KE when it hits the ground using the conservation of energy.
First, let's determine the potential energy of the slab at its maximum height. The potential energy (PE) of an object is given by the formula:
PE = m * g * h
Where:
m = mass of the object (in kg)
g = acceleration due to gravity (approximately 9.8 m/s^2)
h = height (in meters)
Since we are given the weight of the slab (2,500 N), we can convert it to mass using the formula:
Weight = mass * g
2,500 N = m * 9.8 m/s^2
Solving for mass:
m = 2,500 N / 9.8 m/s^2 ≈ 255.1 kg
Now, we can calculate the potential energy (PE) of the slab at its maximum height of 12 meters:
PE = m * g * h
PE = 255.1 kg * 9.8 m/s^2 * 12 m ≈ 29,898.24 J
According to the law of conservation of energy, this potential energy will convert entirely into kinetic energy (KE) as the slab falls.
So, the KE of the slab just before it hits the ground is approximately equal to the potential energy at its maximum height:
KE = PE ≈ 29,898.24 J
Therefore, the kinetic energy of the slab as it hits the ground is approximately 29,898.24 Joules.