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!
Two things are said to be in contact if the smallest distance between a point in one of them and a point in the other one is zero.
Answer:
Behaviour and uses of electromagnetic waves
Radio waves. Radio waves are used for communication such as television and radio. ...
Microwaves. Microwaves are used for cooking food and for satellite communications. ...
Infrared. ...
Visible light. ...
Ultraviolet radiation.
The component of the crate's weight that is parallel to the ramp is the only force that acts in the direction of the crate's displacement. This component has a magnitude of
<em>F</em> = <em>mg</em> sin(20.0°) = (15.0 kg) (9.81 m/s^2) sin(20.0°) ≈ 50.3 N
Then the work done by this force on the crate as it slides down the ramp is
<em>W</em> = <em>F d</em> = (50.3 N) (2.0 m) ≈ 101 J
The work-energy theorem says that the total work done on the crate is equal to the change in its kinetic energy. Since it starts at rest, its initial kinetic energy is 0, so
<em>W</em> = <em>K</em> = 1/2 <em>mv</em> ^2
Solve for <em>v</em> :
<em>v</em> = √(2<em>W</em>/<em>m</em>) = √(2 (101 J) / (2.0 m)) ≈ 10.0 m/s