Which device is using a motor? A. A water heater creates heat energy from electric energy. B. A waterfall rotates a waterwheel t
1 answer:
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Answer:
a ) 4.5 N.s
b) V =5 m/s
Explanation:
given,
mass of rifle(M) = 0.9 kg
mass of bullet(m) = 6 g = 0.006 kg
velocity of the bullet(v) = 750 m/s
a) momentum of bullet = m × v
= 750 × 0.006
= 4.5 N.s
b) recoil velocity
m × u + M × U = m × v + M × V
0 + 0 = 0.006 × 750 - 0.9 × V
V =
V =5 m/s
<h2>Answer:</h2>
<em><u>(a). 16.741 m/s</u></em>
<em><u>(b). 15.75 m/s</u></em>
<h2>Explanation:</h2>In the question,
Height of the cliff, h = 37 m
Time taken to reach the sound to us = 2.92 s
Speed of the sound in air at room temperature = 343 m/s
Now,
Let us say the speed of the ball = u m/s
So,
Time taken by the ball to reach at the bottom, t is given by,
So,
Splash is heard after = 2.92 s
So,
<u>Time taken by sound to travel the shortest distance along the hypotenuse of the triangle</u> thus formed is,
t = 2.92 - 2.747
t = 0.172 s
Now,
Distance traveled by sound is given by,
So,
In the triangle using the Pythagoras Theorem,
Horizontal distance traveled is,
So,
Speed of throwing of ball is given by,
<em><u>Therefore, the speed of the ball = 16.741 m/s.</u></em>
(b).
If,
Speed of sound = 331 m/s
So,
<u>Distance traveled by sound</u> is,
So,
Distance traveled in the horizontal by ball is,
So,
Speed of the ball thrown is given by,
<em><u>Therefore, the speed of the ball = 15.75 m/s.</u></em>