Projectile Question (2 Viewers)

[lilly luta]

A bundle of fireworks is launched from Centrepaint Tower in Sydney, 305m above the ground. It is launched with a valocity of 45m/s at an angle of 30 degree above the horizontal. the fireworks explode at a safe height of 280m above the groud.

a/ What is the initial vertical component of the velocity? (I got that)
b/ What is the maximum heiht reached by the fireworks before they explode? (Got this too
c/How long after the launch do the fireworks explode?
d/ What is the horizontal distance from the tower to the fireworks when they explode?

Please help me with c and d thanks a lot

 

[lilly luta]

Please help (

 

[qrpw]

Consider the vertical part of the initial velocity found in Part A. We can use that, plus a=-9.8 and s=-25m (the distance it travels before it explodes, negative since it is closer to the ground) to find time. I'm sure you can work out which formula to use.
For D just use the time of flight and horizontal velocity.

 

[lilly luta]

where did you get the 25m from?

 

[qrpw]

The fireworks are launched 305m above the ground, and explode 280m above the ground. So in essence, it has travelled -25m vertically (considering up is positive).

 

[lilly luta]

thanks alot for that qrpw

 

[RivalryofTroll]

2:19

 

[zombies]

2:19

Lol oh dear have you memorised all the lyrics?!

 

[lilly luta]

hahaha, love it

 

[Skeptyks]

2:19

I actually like this song kinda haha

 

[zombies]

I actually like this song kinda haha

It's so catchy! I went and downloaded Black and Yellow after watching this.

 

[SpiralFlex]

A)




[HR][/HR]

B)








[HR][/HR]

C)

So,


















[HR][/HR]

D)

 

[madharris]

2:19

erm...

I love how the teachers participated.... or are they randoms?

 

[SpiralFlex]

^Vids old, you 2013ers haven't seen it yet because you weren't around at our time.

 

[zombies]

^Vids old, you 2013ers haven't seen it yet because you weren't around at our time.

Pffft we're only one year younger! I saw it ages ago.

 

[SpiralFlex]

Don't hi-jack threads.

 

[lilly luta]

A)




[HR][/HR]

B)








[HR][/HR]

C)

So,


















[HR][/HR]

D)

Thanks heaps Spiral

 

[Roy216]

hey spiral why is it in part b u made Vy = 0?

 

[nightweaver066]

hey spiral why is it in part b u made Vy = 0?

At maximum height, i.e. the point at which it's not moving up or down (kind of like the maximum turning point of a parabola), the vertical velocity is 0 (Vy = 0).

 

[SpiralFlex]

At maximum height the vertical component of velocity is zero.