do u hv a sharp mind?

Question

if so then solve this problem...
A balloon starts rising from ground with upward acceleration 2m/s^2.After 1s, a stone is dropped from it.Time taken by stone to strike ground is ?explain the whole process.

Answer 1

After 1s, velocity of baloon is -2m/s (- as it is going against earth gravity). As stone is dropped from the baloon, it will have same velocity.
Distance travelled by baloon in 1s is: 1m
Therefore: s = ut + 1/2 a*t^2
1 = -2*t + 1/2*10*t^2 (taking acc due to gravity, g = 10)
1 = -2t + 5t^2
5t^2 - 2t - 1 = 0
t = (2 +/- sqrt(4 + 20))/10
t = (2 +/- 4.9)/10
t = (2 + 4.9)/10 = 0.69 sec
(neglecting - coz negative t is not possible)

Answer 2

Sharp enough to know you're cheating on your homework.

I'll help get you started though:

Calculate the distance the balloon will rise in 1 s, (h)
Calculate the upward velocity of the balloon after 1 s of acceleration at 2 m/s^2, (v)
When the stone is released, it will have the upward velocity of the balloon v and will be at a height h. Figure how long it takes a rock starting at h and with an initial upward velocity of v to fall to the ground given the downward acceleration of gravity (9.81 m/s^2).

The mass of the stone doesn't matter.

Answer 3

The distance formula for an initial velocity of zero and an initial displacement of zero is D = 1/2at^2

And the velocity after time t is just v = at.

So, when released from the balloon, the rock is 1 meter off the ground and has an initial velocity of 2. And, it's new acceleration is -9.8 m/s^2.

The general displacement equation with an initial velocity and an initial displacement is: D = D(0) + V(0)t + 1/2at^2. We want to know how long it takes for the rock to hit the ground. Well, the distance above the ground is zero when you hit the ground. I know, it sounds stupid, but it is a good way to remember how to use the formula. Ok, setting D = 0 and solving:
0 = 1(m) + 2 (m/sec)* t sec + (-9.8 m/sec^2)*t^2 sec^2.

Using the quadratic, t = (-2 +/- sqrt(4+4*1*9.8))/2 =
-1 +/- sqrt(43.2)/2 = -1 +/-sqrt(10.8). We throw out the negative time solution and we get t = sqrt(10.8) - 1. Or, about 2.3 seconds.

Answer 4

The weight of the stone is irrelevant, it will fall at 32 feet per second. the answer is simple enough because all the variables are already present...don't over think the answer.

Answer 5

Seriously, you have all the information to solve this from you other answers, you're just being lazy now. Do your homework. It's not even hard anymore. Everyone has explained the equation to you. Hop to it. I believe in you.

Answer 6

d=vit+.5at^2
d=0+.5(2)(1^2)
d= 1m

d=vit+.5at^2
1=0+.5(9.81)(t^2)
t^2= .20387

i don't have a calculator with me but you can get the answer by finding the square root of .20387

oh yeah
Hillbillies, I hope you were joking

Answer 7

u need the weight of the stone

Answer 8

If your brain was full of hot air...and your boyfriends car was traveling at 60mph how long would it take you to go back in your house and finish your homework? a+b=c I'm leaving

Answer 9

Hmmm, sounds like home work. The answer is one second. you do the math. (Hint, how fast does stuff like a rock fall)

Answer 10

i don't knoe the answer but i know that u r a fan of hilary duff..i think