Question:<em> </em><em>Find, separately, them mass of the balloon and the basket (incidentally, most of the balloon's mass is air)</em>
Answer:
The mass of the balloon is 2295 kg, and the mass of the basket is 301 kg.
Explanation:
Let us call the mass of the balloon
and the mass of the basket
, then according to newton's second law:
,
where
is the upward acceleration, and
is the net propelling force (counts the gravitational force).
Also, the tension
in the rope is 79.8 N more than the basket's weight; therefore,

and this tension must equal


Combining equations (2) and (3) we get:

since
, we have

Putting this into equation (1) and substituting the numerical values of
and
, we get:


Thus, the mass of the balloon and the basket is 2295 kg and 301 kg respectively.
Infared = used by police
gamma = short wavelength
radio = largest wavelength
visible = only ones we can see
Answer:
B, C and E
Explanation:
The unit of resistance in the international system is the Ohm, the equation that describes the resistance is:

Where (l) is for lenght of the wire, (S) is the area and (p) its the constant associated to the conductor.
It's related by the Ohm's Law:

Longitudinal waves transfer energy parallel to the direction of the wave motion
Using the given equation you get:
E = 1.99x10^-25 / 9.0x10^-6
Divide 1.99 by 9.0: 1.99/9.0 = 0.22
For the scientific notation, when dividing subtract the two exponents:
25 -6 = 19
So you now have 0.22 x 10^-19
Now you need to change the 0.22 to be in scientific notation form:
2.2 x 10^-20
The answer is B.