Rock is completely immersed in hot water. By the second law of thermodynamics, thermal energy or heat is transferred from substance with higher temperature to substance with lower temperature until they come to thermal equilibrium i.e. both at same temperature.
It is given here that rock is at 20°C which is at lower temperature than water at 80°C. ∴Heat or thermal energy flows from water to rock. So, right choice is-
A. The water gives the rock thermal energy and gets no thermal energy in return.
Are there any answer choices?
Submarines use <span>buoyancy by filling ballast tanks up with water. When they are filled with water, they are more dense than the surrounding water, so they are able to sink. If they want to rise, they fill these tanks up with air so that the density is less than the water it surrounds.
Hope this helps! :)</span>
Answer:
A- 18
Explanation:
It wont let me explain how
Answer:According to the Equation (2), centripetal force is proportional to the square of the speed for an object of given mass M rotating in a given radius R.
Explanation:The Period T. The time T required for one complete revolution is called the period. For. constant speed. v = 2π r T holds.
Answer:
(a) 6.567 * 10^15 rev/s or hertz
(b) 8.21 * 10^14 rev/s or hertz
Explanation:
Fn= 4π^2k^2e^4m * z^2/(h^3*n^3)
Where Fn is frequency at all levels of n.
Z = 1 (nucleus)
e = 1.6 * 10^-19c
m = 9.1 * 10^-31 kg
h = 6.62 * 10-34
K = 9 * 10^9 Nm2/c2
(a) for groundstate n = 1
Fn = 4 * π^2 * (9*10^9)^2*(1.6*10^-19)^4* (9.1 * 10^-31) * 1 / (6.62 * 10^-31)^3 = 6.567 * 10^15 rev/s
(b) first excited state
n = 1
We multiple the groundstate answer by 1/n^3
6.567 * 10^15 rev/s/ 2^3
F2 = 8.2 * 10^ 14 rev/s
