physics!! help!! asap!!?

Question

2. A swimmer slides freely from rest from the top of a water slide and reaches the bottom with a horizontal speed. He hits the water 4.6m from the slide 0.8 s later. Find the length of the slide.

4. A spring of force constant 1250 N/m is compressed 0.25m. A brick of mass 1.50 kg is palced on top of it. When the spring is released, how high will the brick go?

Answer 1

2.The length of the slide? Or is it the elevation of the slide?

Potential energy (Pe) is converted to kinetic energy (Ke)
Pe=Ke
mgh=0.5mV^2

h=0.5V^2/g
h=0.5 (4.6/0.8)^2 / 9.81=
h=1.69m

4. Again energy conservation.

Energy of the spring Es is
Es=0.5 k x^2
The brick will reach potential energy Pe after relies is
Pe=mgh
h - height above the release point
m - mass of the block
g- acceleration due to gravity


Since Es=Pe

mgh= 0.5 k x^2
h= k x^2 / (2mg)
h= 1250 (.25)^2/(2 x 1.50 x 9.81)
h=2.65m