In a block and tackle, some friction in the pulleys will reduce the mechanical advantage of the machine. To include friction in a calculation of the mechanical advantage of a block and tackle, divide the weight of the object being lifted by the weight necessary to lift it.
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Hi there!
Recall Newton's Law of Universal Gravitation:
Where:
Fg = Force of gravity (N)
G = Gravitational Constant
m1, m2 = masses of objects (kg)
r = distance between objects (m)
Plug in the given values stated in the problem:
Answer:
Doppler effect changes the wavelength of the light emitted, depending upon whether source is moving away or coming towards the observer(detector).
Explanation:
Doppler effect in light is actually a relativistic effect but somewhat similar to the one which happens in sound waves.
When the source is moving away from the detector, the wavelength of the light emitted from the source appears to be increased as seen by the detector, as a result the frequency decreases(we know that frequency of light= speed of light/wavelength of light. Here speed of light is constant and frequency of light is inversely proportional to its wavelength)
Due to this decrease in frequency the light emitted from the source appears more red, since red color is on low frequency side in the electromagnetic spectrum.
Similarly for the source moving towards the detector, the wavelength appears to be decreased, thereby resulting in increase in frequency and the source appears blue. The shift in frequency is known as doppler shift.
The shift in frequency when the source is moving away is known as redshift and the one where the source is moving towards detector is known as blueshift
Rockets can travel through space because there is no force holding or acting on them.So if the rocket travels and a certain velocity it will travel at the same velocity unless a force acts on it
Answer:
17.23 m/s²
Explanation:
Applying the equation of motion,
Δs = ut + 1/2at²..................... Equation 1
Where Δs = change in height of the rocket, u = initial velocity of the rocket, a = acceleration of the rocket, t = time
making a the subject of the equation,
a = 2(Δs-ut)/t²..................... Equation 2
Given: Δs = (56-4) m = 52 m, u = 11.0 m/s, t = 1.90 s.
Substitute into equation 2
a = 2[52-(11×1.9)]/1.9²
a = 2(52-20.9)/1.9²
a = 2(31.1)/3.61
a = 62.2/3.61
a = 17.23 m/s².
Thus the acceleration = 17.23 m/s²
