The statement shows a case of rotational motion, in which the disc <em>decelerates</em> at <em>constant</em> rate.
i) The angular acceleration of the disc (
), in revolutions per square second, is found by the following kinematic formula:
(1)
Where:
- Initial angular speed, in revolutions per second.
- Final angular speed, in revolutions per second.
- Time, in seconds.
If we know that
,
y
, then the angular acceleration of the disc is:


The angular acceleration of the disc is
radians per square second.
ii) The number of rotations that the disk makes before it stops (
), in revolutions, is determined by the following formula:
(2)
If we know that
,
y
, then the number of rotations done by the disc is:

The disc makes 3.125 revolutions before it stops.
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Answer
given,
frequency from Police car= 1240 Hz
frequency of sound after return = 1275 Hz
Calculating the speed of the car = ?
Using Doppler's effect formula
Frequency received by the other car
..........(1)
u is the speed of sound = 340 m/s
v is the speed of the car
Frequency of the police car received

now, inserting the value of equation (1)


1.02822(340 - v) = 340 + v
2.02822 v = 340 x 0.028822
2.02822 v = 9.799
v = 4.83 m/s
hence, the speed of the car is equal to v = 4.83 m/s
Answer:
a) According to Newton's law of gravitation, as the distance between the Moon and the Earth decreases, the gravitational attraction increases and vice versa
The gravitational force of the Moon on the Earth causes the Earth to be slightly bulged on the side directly facing the Moon
The gravitational force also pulls the water bodies on the Earth's surface towards the Moon in the same manner and the effect is more pronounced due to the ability of the liquid water to assume a shape based on the magnitude of the gravitational field attracting it
Therefore, the region where the Moon is closest to the Earth we have a high tide as the water level rises and the region which is perpendicular to where the Moon is located has a low tide
b) The two special types of tides are
1) The neap tide
2) The spring tide
Neap tide
Neap tide occurs when the Sun and Moon are 90° apart from each other when they are viewed by an observer from Earth
The gravitational pull of the Sun cancels (partially) the effect of the gravitational pull and tidal force of the Moon, resulting in minimum tidal range
Spring Tide
Spring tide occurs when the Earth, the Moon, and the Sun are simultaneously inline, such that the Sun reinforces the gravitational pull and tidal force of the Moon, resulting in a maximum tidal range
Explanation:
Answer:
All electromagnetic radiation, regardless of its wavelength, travels at what is called the "speed of light". In a vacuum, it is measured as 299,792,458 meters per second. 3.0 x 108 meters per second.