Answer:
0.786 Hz, 1.572 Hz, 2.358 Hz, 3.144 Hz
Explanation:
The fundamental frequency of a standing wave on a string is given by

where
L is the length of the string
T is the tension in the string
is the mass per unit length
For the string in the problem,
L = 30.0 m

T = 20.0 N
Substituting into the equation, we find the fundamental frequency:

The next frequencies (harmonics) are given by

with n being an integer number and f being the fundamental frequency.
So we get:



Answer:
Explanation:
let force exerted by engine be F.Net force =( F-400)N, applying newton law
F-400 = 1.5 x 10³x18 =27000 ,
F = 27400 N.
velocity after 12 s = 0 + 18 x 12 = 216 m/s
Average velocity = (0 + 216 )/2 = 108 m/s
Average power = force x average velocity = 27400 x 108 = 29.6 10⁵ W .⁶
b) At 12 s , velocity = 216 m/s
Instantaneous power = velocity x force = 216 x 27400 = 59.2 x 10⁶ W.
Answer:
True
Explanation:
The image produced a convex mirror is always virtual irrespective of location. The size of the image is always smaller than the object. In a plane mirror the distance of the object and the distance of the image is same. But in a convex the image distance is always less than the object distance.
So, this statement is true.
Refraction is said to occur when there is a change in the speed of light.
<h3>What is the angle of refraction?</h3>
We know that refraction is said to occur when there is a change in the speed of light as it travels form one medium to another.
Given that the refractive index of the rectangular glass block is 1.5. The angle of refraction can be obtained by the use of the Snell's law;
n = sin i /sinr
n = refractive index
sini = angle of incidence
sin r = angle of refraction
sinr = sini/n
sinr = sin 45/1.5
= 0.471
r = 28 degrees
b) Now;
sinr =sin 45/1.2
sinr = 0.589
r = 36 degrees
For the glass
sinr = sin 36/1.5
sin r = 0.392
r = 23 degrees
Learn more about angle of refraction:brainly.com/question/2660868
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