Answer:
option (B) decreases
Explanation:
According to the Wein's displacement law, the minimum wavelength of the radiated emission is inversely proportional to the absolute temperature of the body which emits radiation.
Where, T is the absolute temperature of the body and λm is the minimum wavelength of heat radiated.
Here, as the temperature increases, the wavelength decreases.
Answer:
76.74 Hz
Explanation:
Given:
Wave velocity ( v ) = 330 m / sec
wavelength ( λ ) = 4.3 m
We have to calculate Frequency ( f ):
We know:
v = λ / t [ f = 1 / t ]
v = λ f
= > f = v / λ
Putting values here we get:
= > f = 330 / 4.3 Hz
= > f = 3300 / 43 Hz
= > f = 76.74 Hz
Hence, frequency of sound is 76.74 Hz.
The impulse required to decrease the speed of the boat is equal to the variation of momentum of the boat:
where
m=225 kg is the mass of the boat
is the variation of velocity of the boat
By substituting the numbers into the first equation, we find the impulse:
and the negative sign means the direction of the impulse is against the direction of motion of the boat.
Answer:
the velocity is 10 m/s
Explanation:
Using the expression for kinetic energy we have:
![Ek=\frac{1}{2} *m*v^{2} \\\\Ek=100J\\m=2kg\\v=\sqrt{(2*100/2)}\\ v=10[m/s]](https://tex.z-dn.net/?f=Ek%3D%5Cfrac%7B1%7D%7B2%7D%20%2Am%2Av%5E%7B2%7D%20%5C%5C%5C%5CEk%3D100J%5C%5Cm%3D2kg%5C%5Cv%3D%5Csqrt%7B%282%2A100%2F2%29%7D%5C%5C%20v%3D10%5Bm%2Fs%5D)
Periodic time is the time taken for one complete oscillation by a body in circular motion. In this case the merry-go round takes 2 minutes to cover 15 complete oscillations. 2 Minutes = 120 seconds
Hence, 15 oscillations takes 120 secs
thus 1 oscillation takes 120/15 = 8 seconds
therefore the period of the merry-go-round = 8 seconds
