I think the answer is “greenhouse effect”
A) 50 cm
B) 10000 cm/s
Explanation
Step 1
A)
If you know the distance between nodes and antinodes then use this equation:

then, let

now, replace to find the wavelength

so, the wavelength is
A) 50 cm
Step 2
The speed of a wave can be found using the equation

or velocity = wavelength x frequency,
then,let

replace and evaluate

so
B) 10000 cm/s
I hope this helps you
A toaster draws electric current (electrical energy) from a wall outlet and converts these moving electric charges into heat (thermal energy) in the filaments that turn red hot to cook your toast. ... As electricity runs through the filaments in a space heater, the electrical energy is converted into heat (thermal energy).
Hopefully this helped.
Convection Current
This happens when there is a noteworthy contrast in temperature between two sections of a liquid. At the point when this temperature distinction exists, hot liquids rise and cool liquids sink, and after that streams, or developments, are made in the liquid
Ke= 1/2 x m x v^2
Ke= 1/2 x 2.1 x 30^2
Energy = 945 J