When a star is moving away from earth it appears blue
Answer:
(a) 1.16 s
(b)0.861 Hz
Explanation:
(a) Period : The period of a simple harmonic motion is the time in seconds, required for a object undergoing oscillation to complete one cycle.
From the question,
If 1550 cycles is completed in (30×60) seconds,
1 cycle is completed in x seconds
x = 30×60/1550
x = 1.16 s
Hence the period is 1.16 seconds.
(b) Frequency : This can be defined as the number of cycles that is completed in one seconds, by an oscillating body. The S.I unit of frequency is Hertz (Hz).
Mathematically, Frequency is given as
F = 1/T ........................... Equation 1
Where F = frequency, T = period.
Given: T = 1.16 s.
Substitute into equation 1
F = 1/1.16
F = 0.862 Hz
Hence thee frequency = 0.862 Hz
Answer:
(a) The resistance of 25m of wire is 3 ohms
(b) the length of this wire that has resistance 22 ohms is 183.33 m
Explanation:
Given;
resistivity of the wire, ρ = 0.12 ohms per meter
(a) The resistance of 25m of wire is calculated as follows;

(b) the length of this wire that has resistance 22 ohms is calculated as;

Answer:
16km
Explanation:
First change the minutes into hours then multiply by the distance.
(8÷60)×120=16km