C and d are the right answers
'C' is a simple explanation of astigmatism.
Answer: 2.5 m/s and 6.25 m
Explanation:
u = 0
a = 0.5 m/s²
t = 5 s
v = u + at
= 0 + 0.5 × 5
= <u>2.5 m/s</u>
s = ut + 1/2 at²
= 1/2 × 2.5 × 5
=<u> 6.25 m</u>
Answer:
v = 7.95 m/s
Explanation:
Given that,
Wavelength of a wave, 
Frequency of a wave, f = 15 Hz
We need to find the speed of the wave. The speed of a wave is given by :
So, the wave move with a speed of 7.95 m/s.
Applicable linear expansion equation:
ΔL = αΔTL
In which
ΔL = change in length, α = Linear expansion coefficient of steel, ΔT = change in temperature, L = original length
Therefore,
ΔL = 12*10^-6*(18.5-(-3))*1410 = 0.36378 m
