FAN + MEDAL
A paper clip is dropped from the top of a 144‐ft tower, with an initial velocity of 16 ft/sec. Its position function is s(t) = −16t2 + 144. What is its velocity in ft/sec when it hits the ground?

Question

FAN + MEDAL
A paper clip is dropped from the top of a 144‐ft tower, with an initial velocity of 16 ft/sec. Its position function is s(t) = −16t2 + 144. What is its velocity in ft/sec when it hits the ground?

arianna1453 · Answer

@Astrophysics @TrojanPoem @ganeshie8  ??

astrophysics · Answer

Note the formula is $$s(t) = - g t^2+v_0t+h_0$$

astrophysics · Answer

So, can you tell me what all the variables mean?

arianna1453 · Answer

No really. Finding velocity confuses me.

ganeshie8 · Answer

s(t) = −16t2 + 144

this is a position function, i think this represents the height above the ground..

ganeshie8 · Answer

the height above the ground is 0 when the clip hits the ground, so shouldn't we be solving

 −16t^2 + 144 = 0

?

trojanpoem · Answer

I think you're correct @ganeshie8 , this is the position so , you should solve for 0.

trojanpoem · Answer

-16 t^2 = -144

t = 3 s

v^2 = v0^2 + 2 as

v = v0 + at = 16 + 32.174 * 3 = 112.52 ft/s

arianna1453 · Answer

Thats what i thoug. Just set it equal to zero. But the only answer choices are -96 -64 -32 0

trojanpoem · Answer

@AlexandervonHumboldt2 , Solve this !