(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A projectile has a time of flight 7.5s and a range 1200m

calculate

(a) its horizontal velocity

(b) Its maximum height

(c) the velocity witch which it is produced

I take a_{y}as -9.8ms^{-2}

2. Relevant equations

r = u_{x}t

d_{y}= u_{y}t + (a_{y}t^{2}/2)

v_{y}^{2}= u_{y}^{2}+ 2ah

u_{x}^{2}+ u_{y}^{2}= u

v = u + at

3. The attempt at a solution

I hope I am the correct

a) r = u_{x}t

u_{x}= r/t

u_{x}= 1200/7.5

u_{x}= 160m

.: Initial Horizontal Velocity is 160m

b)

d_{y}= u_{y}t + (at^{2}/2)

d_{y}= 0 (Total vertical displacement is zero)

0 = 7.5u_{y}- 275.625

7.5u_{y}= 275.625

u_{y}= 36.75

v_{y}^{2}= u_{y}^{2}+ 2ah

v_{y}= 0

0 = 1350.5625 - 19.6h

19.6h = 1350.5625

h = 68.90625 ...

.: Maximum height is 68.91m^{-1}

c)

u_{x}^{2}+ u_{y}^{2}= u

(160)^{2}+ (36.75)^{2}= 26950.5625

u = 164.1662648 ...

.: Initial Velocity is 164.17ms^{-1}

v = u + at

v = (164.1662648) + (-9.8)(7.5)

v = 90.6662648 ...

.: Final Velocity is 90.67ms^{-1}

Ya ?

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Aussie NSW Year 12 Projectile Motion Question.

**Physics Forums | Science Articles, Homework Help, Discussion**