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 : The temperature of the hot reservoir (in Kelvins) is 1128.18 K
Explanation :
Efficiency of carnot heat engine : It is the ratio of work done by the system to the system to the amount of heat transferred to the system at the higher temperature.
Formula used for efficiency of the heat engine.
where,
= efficiency = 0.780
= Temperature of hot reservoir = ?
= Temperature of cold reservoir = 
Now put all the given values in the above expression, we get:
Therefore, the temperature of the hot reservoir (in Kelvins) is 1128.18 K
The answer is meters....I think??
The correct answer is:
c. toward the floor
In fact, we can find the direction of the magnetic force that acts on a positive moving charge by using the right-hand rule:
- index finger: direction of the charge
- middle finger: direction of magnetic field
- thumb: direction of the force
We also have to keep in mind that for a negative charge, we should reverse the direction of the thumb in order to find the correct direction of the force.
In this case:
- index finger: south to north
- middle finger: east to west
- thumb: toward the ceiling
and since the charge is negative, we have to reverse the sign of the thumb, so the magnetic force points toward the floor.
