Answer:
The frequency would double.
Explanation:
Given:
Speed of wave (v) = constant.
Frequency of wave initially (f₁) = 2 Hz
Initial wavelength of the wave (λ₁) = 1 m
Final wavelength of the wave (λ₂) = 0.5 m
Final frequency of the wave (f₂) = ?
We know that the product of wavelength and frequency of the wave is equal to the speed of the wave.
Therefore, framing in equation form, we have:
Wavelength × Frequency = Speed

It is given that speed of the wave remains the same. So, the product must always be a constant.
Therefore,

Now, plug in the given values and solve for 'f₂'. This gives,

Therefore, the final frequency is 4 Hz which is double of the initial frequency.
f₂ = 2f₁ = 2 × 2 = 4 Hz
So, the second option is correct.
The tape is charged by friction and her hand has an induced opposite charge. They therefore attract.
Answer:
(a) Ferromagnet
Explanation:
Ferromagnetism is defined as the property by which certain magnets form the permanent magnets.
It is tone of the strong magnetism and it is common phenomenon of magnet in the everyday life of magnetism.
Permanent magnets are made up of ferromagnetic material, in this if the magnetic field is applied then this material is magnetized but do not losses its magnetic property after removal of external magnetic field.
The one that both benefits each other is the one I think it's mutalistic