Prove law of conservation of energy for a stone moving vertically down ( explain energy at b & c )

As per given condition of point B we can see that height at point B is "h/2" from the ground

So we know that potential energy is given as

U = mgh

so here we have to put height h = h/2

so potential energy is U = mgh/2

now for kinetic energy we need to find the speed of it after falling the distance h/2

now by kinematics we will have

now for kinetic energy

now total energy will be given as

now for point C we can say that it is the point near to ground

So here height is ZERO

now potential energy will also be zero

U = 0

now for kinetic energy we need to find speed

now kinetic energy

now again we have total energy

dec 23, 2016 - a load of bricks weighing 680 n a distance of 10 m across a parking lot. if if the worker pushes the cart with a constant force of 209 n, what work= force x distance = 220 n x 10 m = 2200 n.m = 2200 j i don't know where the person got it from, but the initial part, work= force x distance me.

it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me