A 65kg. person dives into the water from the 10.0 m platform 1. I know the speed.

[grahmedmisten2]

She stops 4.0 m. below the surface of the water. Find the force on the swimmer by water


Would it just be vf^2=vi^2+2(9.8)(10)

This is a physics question.

Since we know he velocity is 0 when the person hits the water

 

[lev888]

Since we know he velocity is 0 when the person hits the water

Why?

 

[Deleted member 4993]

She stops 4.0 m. below the surface of the water. Find the force on the swimmer by water


Would it just be vf^2=vi^2+2(9.8)(10)

This is a physics question.

Since we know he velocity is 0 when the person hits the water

Incorrect.

The velocity at the surface of the water (diving from 10 m board) should be from the above equation (starting with v_i =0 at the top of the board).

v_s^2=v_i^2+2(9.8)(10) \(\displaystyle \ \to \ \) v_s = \(\displaystyle \ \sqrt{1.96}\)

Now calculate the amount of "deceleration" needed to stop her in 4m (same equation as above) - but different "unknown" and "givens".

Then calculate the force using F = m * a

 

[HallsofIvy]

She stops 4.0 m. below the surface of the water. Find the force on the swimmer by water


Would it just be vf^2=vi^2+2(9.8)(10)

This is a physics question.

Since we know he velocity is 0 when the person hits the water

We know her velocity is 0 when the person is "4.0 m below the surface of the water", not "when the person hots the water"!