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
The statement about "<span>efficiency compared the output work to the output force" is false. Efficiency can be compared from the input work to the output work.</span>
Answer: A) Transformer
Explanation: A Transformer is an apparatus, device or a component in a system that is used to convert high voltage into low voltage. It is used to either increase or decrease the voltage of an alternating current.
A transformer uses the basic principle of electro magnetic induction, having two or more coils, the voltage is changed from one coil to another but with thesame frequency as alternating current energy passes through them.