How Do You Solve Projectile Motion Problems Involving Angles and Heights?

[TheKovac]

Homework Statement

A object is projected with a velocity of 100 m/s at an elevations 30 degrees from a tower 150m high.

a) Time of flight
b) The horizontal distance from the tower at which the stone strikes that ground.
c) The magnitude and the direction of the velocity of the stone striking the ground.

Homework Equations

x=ut+0.5at^2
Trigonometry
v^2 = u^2 + 2ax

The Attempt at a Solution

a)

=>v=u+at
50.2=100 -10t
t1= 5.02s
t2 = 5.02s
t3=?

Am I on the right track at all?

 

[gshyam]

Homework Statement

A object is projected with a velocity of 100 m/s at an elevations 30 degrees from a tower 150m high.

a) Time of flight
b) The horizontal distance from the tower at which the stone strikes that ground.
c) The magnitude and the direction of the velocity of the stone striking the ground.

Homework Equations

x=ut+0.5at^2
Trigonometry
v^2 = u^2 + 2ax

The Attempt at a Solution

a)

=>v=u+at
50.2=100 -10t
t1= 5.02s
t2 = 5.02s
t3=?

Am I on the right track at all?

what are these t1 t2 and t3 ?
If you have the book PHYSICS by Resnic and Haliday please look in it for the solution.
bye

 

[Dr. Jekyll]

You have some help https://www.physicsforums.com/showthread.php?t=227924".

For the (a) part you have vertical shot (y component of the velocity) and then free fall from the height of 150 m at initial velocity of $$v_{y}=v_{0}sin\alpha.$$

For the (b) part you need the x component. You have the time from the (a) part, so it's pretty easy.

(c) part is also simple. You need the net velocity (trigonometry). X component doesn't change but the y component is increased by gravity.