A football player kicks a 0.70 kg ball to the left with velocity of 25.0 m/s . If the player exerts an average force of 70 N to the left on the ball, how long the ball's take to reach a velocity of 40.0 m/s to the left?

What object a collides with object b and bounces back its final momentum is?

What determines the amount of inertia an object has

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.