Answer:
Hydrated iron(III) oxide, or ferric oxide
Explanation:
The answer to this question is C. The reason why this is an incorrect statement is that the Doppler effect takes into account two moving objects. In this scenario, both the source and the listener are stationary to the frequency of the sound waves will not change due to the Doppler effect. For the other answers, the frequency of sound waves is not affected by nature of the medium. The distance between a sound source and listener does not alter the frequency of the sound wave. The frequency of the sounds waves remains the same to the listener.
Answer:
option (d) 7.1 kN
Explanation:
Given:
Mass of the car, m = 1600 kg
Acceleration of the car, a = 1.5 m/s²
Coefficient of kinetic friction = 0.3
let the tension be 'T'
Now,
ma = T - f .................(1)
where f is the frictional force
also,
f = 0.3 × mg
where g is the acceleration due to the gravity
thus,
f = 0.3 × 1600 × 9.81 =
therefore,
equation 1 becomes
1600 × 1.5 = T - 4708.8
or
T = 2400 + 4708.8
or
T = 7108.8 N
or
T = 7.108 kN
Hence,
The correct answer is option (d) 7.1 kN
