Solve 2D Projectile Motion Problems with Sample Equations and Steps

[tmay]

Homework Statement

g'day everyone,

First of all, i would like to thank everyone on this site. You lot have helped me a lot with my homework over the last couple of weeks. anyway to the question.

A golf ball is struck at ground level. The speed of the ball as a function of the time is attached, where t = 0 at the instant the ball is struck.

A) how far does the ball travel horizontally before returning to the ground level?

B) what is the max height above the ground level attained by the ball?

Homework Equations

A)
x-x0 = (v0cos theta)t

B)
y-y0 = (v0sin theta)t - 1/2gt^2

The Attempt at a Solution

I am stuck on this question. i don't know were to start. were not given theta or the final x position or the y value. I am sure the answer to this question is in the graph and i am just not reading it properly.

from the graph i have established that the ball is in the air for 5 sec. and that the initial velocity is 31m/s. however this isn't enough information to work out the questions. any help would be greatly appreciated

 

[tiny-tim]

Welcome to PF!

B)
y-y0 = (v0sin theta)t - 1/2gt^2

Hi tmay! Welcome to PF!

(have a theta: θ and try using the X₂ tag just above the Reply box )

You know y - y₀ and v₀ and t, so θ = … ?

 

[tmay]

thankyou tiny - tim.

i now know how to get the answer.