Answer:
0.25 cm³.
Explanation:
We shall apply Boyle's law to find the solution . According to it
PV = constant where P is pressure and V is volume of the gas.
P₁ V₁ = P₂V₂
1 x .5 = 2 x V₂
V₂ = 0.25 cm³.
P= mv
where p is momentum
m is mass
v is velocity
so it's given p= 100kgm/sec
v= 4m/s
so putting in the formula
100= m × 4
m = 25kg
Coal power, using fossil fuels.
Answer:

Explanation:
<u>Rate Of Change</u>
Let some variable y depend on time t. we can express y as a function of t as

The instant rate of change of y respect to t is the first derivative, i.e.

The balloon, the ground and the observer form a right triangle (shown below) where the height of the balloon y, the horizontal distance x, and the angle of elevation are related with the trigonometric formula

Since x is constant, we take the derivative with respect to time by using the chain rule:

Solving for 

Let's compute the actual angle with the initial conditions y=9 feet, x=12 feet


Knowing that



The balloon is rising at y'=8 feet/sec, thus we compute the change of the angle of elevation:



Ice.... glass...bottle...metal