Physics Problems 2?

Question

Please just provide aswers because its too much work, i just want to verify if mine are right. If you could, provide the equation used

An object thrown straight up from the ground level returns to the ground in 5 sec. Find its initial velocity.

A stone is dropped fromt he roof of a building 58 m high. What is the stone's velocity just before it hits the sidewalk

A stone is thrown vertically upward with an initial speed of 12 m/s. Determine the position and the velocity of the stone at t=1.6sec

A 72 kg man stands on a spring scale in an elevator. Starting from rest, the elevator descends attaining its maximum speed of 1.2m/s in 0.8 sec. Then the elevator come to rest in 1.5 sec. What does the spring scale register a) before the elevator start to move b) during the first 0.8 s c) when it is slowing down

A 10 kg block is pulled by a cord that makes a 25degree angle with a horizontal. The tention force in the cord has a magnitude of 20N. Find normal force on the block

Answer 1

1.)gt=Vo = 49.05 m/s
2.)t=sqr((vy-vo)/g)
g(sqrt((vy-vo)/g)) = 33.73 m/s
3.) v=-3.969 m/s
y=6.6432 m
4.)a.706.32 N
b.619.92 N
c.792.72 N
5.)78.8 N

Answer 2

This is just one of the pages I used to understand and check my physics homework...Hopefully it is still working.

Kitty
http://sciencepage.org/physics.htm