Answer:
Turn the heater on
Explanation:
There are two main forces involved in a balloon flight
The downward force is the total weight of the balloon: the air it contains, the gas bag, the basket, the passengers, etc.
The upward force is the weight of the of the air the balloon displaces.
During level flight
,
buoyant force = weight of displaced air - total weight of balloon
If you increase the temperature of the air in the bag, the air molecules spread out and leave through the bottom of the bag.
The balloon still has the same volume, so the weight of displaced outside air stays the same.
However, the balloon has lost some hot inside air, so its total weight decreases.
The upward force is greater than the downward force, so the balloon rises.
Answer:
108.37°C
Explanation:
P₁ = Initial pressure = 101 kPa
V₁ = Initial volume = 530 m³
T₁ = Initial temperature = 10°C = 10+273.15 =283.15 K
P₂ = Final pressure = 101 kPa (because it is open to atmosphere)
V₂ = Final volume = 530 m³
P₁V₁ = n₁RT₁
⇒101×530 = n₁RT₁
⇒53530 J = n₁RT₁
P₂V₂ = n₂RT₂
⇒53530 J = n₂RT₂

Dividing the first two equations we get

∴Temperature must the air in the balloon be warmed before the balloon will lift off is 381.25-273.15 = 108.37°C
Answer: 154.08 m/s
Explanation:
Average acceleration
is the variation of velocity
over a specified period of time
:

Where:

being
the initial velocity and
the final velocity

Then:

Since
:

Finding
:


Finally:

Answer:
The rate of change of the distance is 14.89.
Explanation:
Given that,
Distance = 145 miles
Speed of car = 42 miles/hr
Distance covered by car = 55 miles
We need to calculate the the rate of change of the distance
According to figure,
Let OA is x, and AB is y.
Now, using Pythagorean theorem

On differentiating




Hence, The rate of change of the distance is 14.89.
D) Less than 20.
Explanation:
Equivalent resistance in a parallel combination is less than their individual value.