I think its C not sure tho
Answer:
The focal lenth (F) =+10.0cm
Explanation:
The formular for combined focal length (F) is given as;

In this question,
F1 = 20cm
F2 = -30cm
Plugging the values into the formuar above,

![1/f = 0.05 - 0.033[tex]1/f = -0.017f = [tex]1/ -0.017](https://tex.z-dn.net/?f=1%2Ff%20%3D%200.05%20-%200.033%3C%2Fp%3E%3Cp%3E%5Btex%5D1%2Ff%20%3D%20-0.017%3C%2Fp%3E%3Cp%3Ef%20%3D%20%5Btex%5D1%2F%20-0.017)
f = 58.82cm
i.e. the combination behaves as a converging lens (because of the postive sign) of focal length 58.82cm .
Answer:

Explanation:
Let's use the equation that relate the temperatures and volumes of an adiabatic process in a ideal gas.
.
Now, let's use the ideal gas equation to the initial and the final state:

Let's recall that the term nR is a constant. That is why we can match these equations.
We can find a relation between the volumes of the initial and the final state.

Combining this equation with the first equation we have:


Now, we just need to solve this equation for T₂.

Let's assume the initial temperature and pressure as 25 °C = 298 K and 1 atm = 1.01 * 10⁵ Pa, in a normal conditions.
Here,
Finally, T2 will be:

1 newton is the force needed to accelerate 1 kilogram of mass
at the rate of 1 meter per second² .
1 N = 1 kg-m/s² .
It's a force equal to roughly 3.6 ounces.