Kinematics balloon problem help

In summary, a student drops a water balloon from a dorm window when their physics professor is walking below. Using the given measurements, it is determined that the balloon will hit the ground before the professor reaches the point directly beneath the window.
  • #1
Mitchtwitchita
190
0

Homework Statement



A student at a window on the second floor of a dorm sees his physics professor coming along the walkway beside the building. He drops a water balloon from 18.0 m above the ground when the prof is 1.00 m from the point directly beneath the window. If the prof is 180 cm tall and walks at a rate of 0.450 m/s, does the balloon hit his head?

The Attempt at a Solution



Yo = 0
y = -18.0 m + 1.8 m = -16.2 m
g = -9.81 m/s^2
Vo = 0
X = 1.00 m
Vxo = 0.450 m/s

Balloon Drop:

y = yo + Vo*t - 1/2*g*t^2
-16.2 m = 0 + 0 - 1/2(9.81 m/s^2)t^2
t^2 = 16.2 m/4.9 m/s^2
t^2 = 3.31 s^2
therefore, t = sqrt3.31 s^2
= 1.82 s

Professor Walk:

x = Vxo*t
1.00 m = (0.450 m/s)t
t = 1.00 m/(0.450 m/s)
=2.22 s

Therefore, the balloon drops before the professor gets there.

Can anybody please tell me if my attempt is o.k.?
 
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  • #2


Looks fine to me.
 
  • #3


Thanks Kurdt!
 

1. How do I calculate the acceleration of a balloon in a kinematics problem?

In a kinematics balloon problem, the acceleration can be calculated using the formula a = (v2-v1)/t, where v2 is the final velocity, v1 is the initial velocity, and t is the time interval.

2. What is the relationship between position, velocity, and acceleration in a kinematics balloon problem?

In a kinematics balloon problem, position is the displacement of the balloon, velocity is the rate of change of position, and acceleration is the rate of change of velocity. These three quantities are related by the kinematic equations.

3. How do I determine the displacement of a balloon in a kinematics problem?

To determine the displacement of a balloon in a kinematics problem, you can use the formula x = x0 + v0t + (1/2)at^2, where x is the final displacement, x0 is the initial displacement, v0 is the initial velocity, t is the time interval, and a is the acceleration.

4. What is the difference between average velocity and instantaneous velocity in a kinematics balloon problem?

Average velocity is the total displacement divided by the total time interval, while instantaneous velocity is the velocity at a specific moment in time. In a kinematics balloon problem, the instantaneous velocity can be found by taking the derivative of the position equation.

5. How do I solve for time in a kinematics balloon problem?

To solve for time in a kinematics balloon problem, you can use the formula t = (v2-v1)/a, where v2 is the final velocity, v1 is the initial velocity, and a is the acceleration. This formula can be derived from the kinematic equations.

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