Answer:
<em>Radius at liftoff 8.98 m</em>
Explanation:
At the working altitude;
maximum radius = 24 m
air pressure = 0.030 atm
air temperature = 200 K
At liftoff;
temperature = 349 K
pressure = 1 atm
radius = ?
<em>First, we assume balloon is spherical in nature,</em>
<em>and that the working gas obeys the gas laws.</em>
from the radius, we can find the volume of the balloon at working atmosphere.
Volume of a sphere = 
volume of balloon = 
x 3.142 x 
= 57913.34 m^3
using the gas equation,
= 
<em>The subscript 1 indicates the properties of the gas at working altitude, and the subscript 2 indicates properties of the gas at liftoff.</em>
imputing values, we have
= 
0.03 x 57913.34 x 349 = 200V2
V2 = 606352.67/200 = <em>3031.76 m^3 this is the volume occupied by the gas in the balloon at liftoff.</em>
from the formula volume of a sphere,
V = = x 3.142 x 
= 3031.76
4.19 = 3031.76
= 3031.76/4.19
radius r of the balloon on liftoff = ![\sqrt[3]{723.57}](https://tex.z-dn.net/?f=%5Csqrt%5B3%5D%7B723.57%7D)
= <em>8.98 m</em>
Answer:
ball will oscillate in between the plates
Explanation:
The metallic coated styrofoam lowered in between two large metal plates, a large potential difference V is kept between the two plates, will experience a force of repulsion ( because both plates and balls will have similar kind of charges and like charges repel each other) from the opposite plates.
If we consider d as the distance between the plates, E as electric field because of Potential difference V. Then force F experience by the ball will be
where q be the total charge on the metallic coated ball.
clearly, since, both the plates will repel the ball in opposite directions, hence ball will be in oscillate in between the plates.
How do we find the Average Speed ?
The Average Speed is the distance traveled for the object, divided by the elapsed time taken to travel that distance, so the formula is :
<em>S = D / T</em>
where S = Average Speed, D = Distance, and T = Times
Here the object is the ball, the distance is 9 meters and the time elapsed for the ball to roll down the street is 3.5 seconds. Applying the formula we get :
S = 9 / 3.5 ≈ 2.6 metres per second
The ≈ symbols (which is the <em>wavy equal sign</em>) means we can't write the exact result, because there is an infinite quantity of numbers after the decimal point. So we need to give an approximation, since the result is 2.57142857142857...etc. we choosed to round up the result to 2.6.
