A Physics Kinematics Grade 11 question

[AudenCalbray]

Homework Statement

Emanual Zacchini was shot over three ferris wheels, landing in a net at the same height from which he was shot. Given his initial velocity of 27m/s [53degrees U of R] and range of 69m, find

a) his maximum height reached
b) the time spent in air, using two different methods
c) his final velocity, using logic and computation.

Homework Equations

v= deltaD/deltaT
a= deltaV/deltaT
V2=V1+adeltaT

The Attempt at a Solution

I found a value for the time from his launch to the maximum height (1.28s), but it's wrong. I know his final velocity is 27 m/s, but I need help for the rest. Thanks!

 

[Sniperman724]

use the mini-van equation Y=Yo + volt + 1/2gt^2 and x=vt

also, break his initial velocity into components and try to solve it that way

 

[AudenCalbray]

Um.. I don't know what you mean! I'm sorry, I don't know what the mini-van equation is.. Could you perhaps explain it a little more?

 

[Delphi51]

Sketch an arrow for the 27 m/s at angle 53 degrees.
Complete the right triangle around this with a horizontal line and a vertical line. Use trigonometry to find the horizontal part and the vertical part. These are the initial velocities in the horizontal and vertical directions.

For the horizontal part of the calculation, there is no acceleration so the formula is just d = vt.

For the vertical part, there is acceleration of -9.81 m/s² so use the accelerated motion formulas for d and v.

Put all the numbers you know into these three equations. You will be able to solve one of them for something - hopefully time - and then you can use the others to find the other quantities you are asked for.

Good luck!

 

[AudenCalbray]

Thank you! I'll try that! Thanks so much for your time and help

 

[Chronos]

It helps to remember acceleration is zero at the top of the arc, and area under the time - velocity curve represents distance traveled.

 

[Delphi51]

acceleration is zero at the top of the arc

That would be vertical velocity zero at maximum height. Acceleration is constant for the whole flight.

 

[AudenCalbray]

Thanks for all your help, guys. I figured out the problem. Thanks for your time and help. :)