How to understand physics
1 answer:
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Answer:
93.75 m/s
Explanation:
Given:
The frequency of the sound = 750 Hz
The number of pistons making the sound = 8
Revolutions made by the engine = 2000 revolutions/ km
Thus,
the frequency of sound by 1 piston = 750 / 8 = 93.75 Hz
also, it is given that for every other revolution sound is made.
thus, for every 2 revolution sound is made
therefore,
Number of revolutions per second = 93.75 Hz × 2 = 187.5 rev/s
Now,
the speed of the car will be calculated as:
= Number of revolutions per second / Revolutions made by the engine
or
The speed of the car =
or
The speed of the car = 0.09375 km/s = 93.75 m/s
Answer:
Speed of lighter ball is 4 m/s.
Explanation:
Applying the principle of conservation of linear momentum,
momentum before collision = momentum after collision.
+
=
-
= 3 kg,
= 8 m/s,
= 2 kg,
= 0 m/s ( since it is at rest),
= 2 m/s,
= ?
(3 x 8) + (2 x 0) = (8 x 2) - (2 x )
24 + 0 = 16 - 2
2 = 16 - 24
2 = -8
=
= -4 m/s
This implies that the light ball moves at the speed of 4 m/s in the opposite direction of the heavier ball after collision.