You are on a rooftop and you throw one ball straight down and another straight up. the second ball, after rising, falls and also strikes the ground below.

if air resistance can be neglected and if your downward and upward initial speeds are the same, how will the speed of the balls compare upon striking the ground?

1. the speed of the second ball is smaller than that of the first one.

2. the speed of the second ball is larger than that of the first one.

3. they have same speed.

4. more information is needed

Asheet of steel 1.5 mm thick has nitrogen atmospheres on both sides at 1200oc and is permitted to achieve a steady-state diffusion condition. the diffusion coefficient for nitrogen in steel at this temperature is 6 x 10- 11 m2 /s, and the diffusion flux is found to be 1.2 x 10-7 kg/m2 -s. also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 4 kg/m3 . how far into the sheet from this high-pressure side will the concentration be 2.0 kg/m3 ? assume a linear concentration profile.

10 points! will mark brainiest! in a heat engine if 1,000 j of heat enters the system and the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2,000 j 1: write the equation 2: list out your known variables 3: plug the numbers into the equations 4: solve 5: write your solution statement that includes initial energy and final energy added you so much!

Debris produced by mining is called