A ball is thrown vertically upwards in the air. Which of the following statements about the motion of the ball is false?
A: The ball will be travelling as fast as it was when it gets back to the ground
as it was when first thrown upwards.
B: The ball will be stationary for an instant at the highest point in its flight.
C: The direction of the force on the ball changes so the ball falls back to the
ground.
D: The direction of the acceleration is always downwards.

Stion 13 of 20 : select the best answer for the question. 13. if a certain mass of mercury has a volume of 0.002 m3 at a temperature of 20°c, what will be the volume at 50°c? a. 0.002021624 m3 b. 0.004021624 m3 c. 0.000010812 m3 d. 0.002010812 m3

Free runners jump long distances and land on the ground or a wall. how do they apply newton’s second law to lessen the force of impact?

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.