The forces of gravity between two objects are inversely proportional to
the square of the distance between them. So reducing the distance
by 1/2 means increasing the gravitational force by 2² = 4 times.
The 1 million newtons becomes 4 million newtons.
Note that this does NOT mean the satellite's altitude above the surface.
When you're calculating gravitational forces, it's the distance between
the centers of the objects. So the question is a meaningful exercise
only if we use the distance between the satellite and the planet's center.
Terminal velocity is the velocity at which a falling body experience
when its weight is equal to the force resistance of force opposing the
fall.
At terminal velocity the acceleration of the body is zero,
which implies that the value of the this velocity is a uniform.
Answer:
you could talk about the people and say something like change
Explanation:
Missing part in the text of the problem:
"<span>Water is exposed to infrared radiation of wavelength 3.0×10^−6 m"</span>
First we can calculate the amount of energy needed to raise the temperature of the water, which is given by

where
m=1.8 g is the mass of the water

is the specific heat capacity of the water

is the increase in temperature.
Substituting the data, we find

We know that each photon carries an energy of

where h is the Planck constant and f the frequency of the photon. Using the wavelength, we can find the photon frequency:

So, the energy of a single photon of this frequency is

and the number of photons needed is the total energy needed divided by the energy of a single photon:
Answer:
Explanation:
The only thing I can figure you need here is the accleration of the sled. The equation we need to find this is Newton's Second Law that says that sum of the forces acting on an object is equal to the object's mass times its acceleration. For us, that looks like this because of the friction working against the sled:
F - f = ma but of course it's much more involved than that simple equation! We have the F value as 230 N, and we have the mass as 105, but we do not have the frictional force, f, and we need it to solve for a in the above equation. We know that
f = μ
where μ is the coefficient of friction, and
is the normal force, aka weight of the object. We will use the coefficient of friction and find the weight in order to fill in for f:
so
so the weight of the sled is
1.0 × 10³ with the correct number of sig dig there. Now to find f:
f = (.025)(1.0 × 10³) so
f = 25 to the correct number of sig fig. Now on to our "real" equation:
F - f = ma and
230 - 25 = 105a. We have to do the subtraction first, round, and then divide since the rules for addition and subtraction are different from the rules for dividing and multiplying.
230 - 25 will round to the tens place giving us 210. Then
210 = 105a. 210 has 2 sig figs in it while 105 has 3, so we will divide and round to 2 sig fig:
a = 2.0 m/sec²