Question

Could you please help me out with the following problems please?

If a rocket initially at rest accelerates at a rate of 50 m/s^2 for one minute, its speed will be ? ( I know there are 60 seconds in 1 minute, so would I just use the formula, d=vt, and I would get 3000 m/s)


It takes 6 seconds for a stone to fall to the bottom of a mine shaft. How deep is the shaft? (This one, I don't understand)

If a projectile is fired straight up at a speed of 10 m/s, the total time to return to its starting position is about (This one I don't understand)

A man leans over the edge of a cliff and throws a rock upward at 4.9 m/s. How far below the level from which it was thrown is the rock 2 seconds later? (would the formula for this one be d=vt (4.9m/s)(2s)= 9.8 m/s

Answer 1

1. No, don't use d=vt. That formula is average velocity * time, and you have neither. vfinal=vinitial + acceleration*time is the one to use.

2. d=vinitial + 1/2 g t^2

3. hfinal=hinitial + vinitial*time + 1/2 g*time^2

Answer 2

A block of mass, m, starts from rest and slide without friction down an incline. a) What is the acceleration of the block while itis in contact with the incline? b). If the block leaves with a speed of 5 m/s what is the length of the incline? If the block lands on floor 3m away how long does it take for the block to fall from the edge of the incline to the floor?