Answer:
λ = hv
If frequency is doubled :
λ = h × 2v
λ = 2hv
Thus wavelength is doubled
Answer:
The answer is D. density.
Answer:

Explanation:
When the block is displaced by x units
F= spring force
two springs are connected parallel

Writing Newtons second law, F = ma


a= x" ( differentiating x w.r.t time twice)

this the standard form of equation of oscillation spring mass system
This is the differential equation, x'' means that double differentiation of x , i.e, x'' is acceleration
since, Period 
therefore,
