Answer:
dr/dt = -2 cm/s.
Explanation:
The volume of a cone is given by:
(1)
- r is the radius
- h is the height
Let's take the derivative with respect to time in each side of (1).
(2)
We know that:
- dh/dt = 10 cm / s (rate increasing of height)
- dV/dt = 0 (constant volume means no variation with respect of time)
- r = 4 cm
- h = 10 cm
We can calculate how fast is the radius changing using the above information.
Therefore dr/dt will be:
The minus signs means that r is decreasing.
I hope it helps you!
<h3><u>Answer;</u></h3>
a) 5.00 x 10^8 J
<h3><u>Explanation;</u></h3>
The work done to move the sailboat is calculated through the equation;
W = F x d
where F is force and d is the distance.
Substituting the known values from the given above,
W = (5.00 x 10⁴ N)(10 km)(1000 m/ 1km)
= 5.00 x 10⁸ J
Thus, the work done is <u>5.00 x 10⁸Joules</u>
Answer:
L = 130 decibels
Explanation:
The computation of the sound intensity level in decibels is shown below:
According to the question, data provided is as follows
I = sound intensity = 10 W/m^2
I0 = reference level = 
Now
Intensity level ( or Loudness)is
Therefore
L = 13 bel
And as we know that
1 bel = 10 decibels
So,
The Sound intensity level is
L = 130 decibels
Answer:
Explanation:
To solve this problem we use the formula for accelerated motion:
We will take the initial position as our reference (
) and the downward direction as positive. Since the rock departs from rest we have:
Which means our acceleration would be:
Using our values:
Answer:
Energy conservation.
Explanation:
The 1st Law of Thermodynamics is a statement about energy conservation. It states that 
, which means that if we <u>substract the work W done</u> by the system to the <u>heat Q given</u> to the system we get the <u>change in the internal energy</u> 
, so any excess in energy given to the system appears as internal energy, stating that energy is conserved.
