Explanation:
first, find the circumference of the wheel by using the formula 2(pi)(r):
2(pi)(19) = 119.380521
divide by 25 secs
119.380521/25 = 4.77522083
round to the nearest tenth is 4.8, so the speed is 4.8mm/sec
Answer:
Explanation:
frequency of whistle = 1.85 x 10² = 185 Hz
frequency of beat heard = 8 beat /s . No of beat produced is equal to difference of frequencies of two sound source . Here difference is created due to Doppler effect . One of the train is moving so it will have apparent frequency which is different one from its original frequency .
When the moving train is approaching the observer , its frequency will be higher . As beat is heard at the rate of 8 beats / s , apparent frequency of approaching train will be 185 + 8 = 193 Hz .
Applying Doppler's formula of apparent frequency ,
193 = 185 x V / ( V - v ) , where V is velocity of sound and v is velocity of train .
193 V - 193 v = 185 V
193 v = 8 V
v = 8 x V / 193
= 8 x 343 / 193
= 14.21 m /s
Second possibility is that apparent velocity is less ie 185 - 8 = 177 Hz
In that case moving train will be moving away from observer . If its velocity be v
177 = 185 x V / ( V + v )
177 V + 177 v = 185 V
v = 8 x 343 / 177
= 15.50 m /s .
Answer:
E = 1.711 MeV
Explanation:
From the law of the conservation of energy:
where,
the kinetic energy of positron and electron = 1.2 MeV
Rest energy of the electron and the positron = 0.511 MeV
E = Energy of Photon = ?
Therefore,
<u>E = 1.711 MeV</u>
Answer:
F=mv^2÷r
Explanation:
i know every thing
the magnitude f of the centripetal force is equal to the mass m of the body times it veloctiy squared v^2 divided by the radius r of its path
Walking at a speed of 2.1 m/s, in the first 2 s John would have walked
(2.1 m/s) (2 s) = 4.2 m
Take this point in time to be the starting point. Then John's distance from the starting line at time <em>t</em> after the first 2 s is
<em>J(t)</em> = 4.2 m + (2.1 m/s) <em>t</em>
while Ryan's position is
<em>R(t)</em> = 100 m - (1.8 m/s) <em>t</em>
where Ryan's velocity is negative because he is moving in the opposite direction.
(b) Solve for the time when they meet. This happens when <em>J(t)</em> = <em>R(t)</em> :
4.2 m + (2.1 m/s) <em>t</em> = 100 m - (1.8 m/s) <em>t</em>
(2.1 m/s) <em>t</em> + (1.8 m/s) <em>t</em> = 100 m - 4.2 m
(3.9 m/s) <em>t</em> = 95.8 m
<em>t</em> = (95.8 m) / (3.9 m/s) ≈ 24.6 s
(a) Evaluate either <em>J(t)</em> or <em>R(t)</em> at the time from part (b).
<em>J</em> (24.6 s) = 4.2 m + (2.1 m/s) (24.6 s) ≈ 55.8 m
