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

A projectile is fired with an initial speed of 65.2m/s at an angle of 34.5deg above the horizontal on a long flat firing range. Determine

(a) the maximum height reached by the projectile,

(b) the total time in the air,

(c) the total horizontal distance covered (that is, the range)

(d) the velocity of the projectile 1.50s after firing

2. Relevant equations

v = v_{o}+at

x = x_{o}+ v_{o}t + .5at^{2}

v^{2}= v_{o}^{2}+ 2a(x - x_{o})

x=vt

3. The attempt at a solution

First I wanted to find out the initial velocity in the x and y direction so i made a right triangle with the hypotenuse as 65.2 m/s with an angle of 34.5 from here I solve for opposite (sin34.5 = opp/65.2) and got 36.929. Then i solved for adjacent (cos34.5 = adj/65.2) and got 53.733. the adjacent is my X_{o}and the opposite is my Y_{o}.

a. the maximum height reached

Equation v^{2}= v_{o}^{2}+ 2a(y - y_{o})

0= 36.929^{2}+ 2(-9.8)(y)

-1363.75 = -19.6y

y = 69.579 i rounded to 69.6m

b. total time in the air

Equation y = y_{o}+ v_{o}t + .5at^{2}

0 = 0 + 36.929(t)+ .5(-9.8)(t^{2})

-4.9t^{2}+ 36.929t + 0 = 0

form here I did a quadratic and got t = 7.536 I rounded to 7.5s

c. the total horizontal distance covered (that is, the range)

Equation x = x_{o}+ v_{o}t + .5at^{2}

x = 0 + 53.733(7.5) +0

x = 402.99 I rounded to 403m

d. the velocity of the projectile 1.50s after firing

Equation v_{y}= v_{oy}+at

v_{y}= 36.929 + -9.8(1.5)

v_{y}= 22.229 I rounded to 22.2m/s

Are my solutions and use of formulas for this problem correct?

Thanks for your help!

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

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

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!

# Homework Help: Projectile Motion Firing Question

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