2nd time posting bc i still need HELP! PHYSICS!!!!
posted by MC on .
The velocity of a diver just before hitting the water is -8.6 m/s, where the minus sign indicates that her motion is directly downward. What is her displacement during the last 0.86 s of the dive?
im so stuck. i tried this problem several times, and my answers werent correct. please help me.
I had a problem similar to this but I was using -11.4 m/s and 1.35 s. You can use my calculations below and just plug in your numbers.
Velocity of diver just before hitting the water,Vf = - 11.4 m/s
Time, t = 1.35 s
Velocity of diver before 1.35 s = Vi
Vf = Vi - g t
- 11.4 = Vi - 9.8 * 1.35
- 11.4 = Vi - 13.23
Vi = 13.23 - 11.4
= 1.83 m/s
Displacement during 't' s , S = [ ( Vi + Vf ) /2 ] t
= [ ( 1.83 - 11.4 ) / 2 ] * 1.35
= - 6.46 m
Vf=Vo+gt where Vf is velocity just before hitting water, and Vo is at the start of the .86
So the average velocity is 8.49, displacement then is downward 8.49*.86 meters