Answer: Probably at-least 30 mins to an hour
Answer:
Explanation:
Since the sound bouncing back from car has greater frequency , the car must be moving towards the police car . If v be the velocity of car
f = 
f is apparent frequency , f₀ is original frequency , V is velocity of sound and v is velocity of car
1270 = 
1.02419 = 
348.22-1.02419v =340 +v
2.02419v = 8.22
v = 4.06 m /s
B)
In this case , we shall take relative velocity in place of velocity of car .So
v = 20+4.06
= 24.06 m /s
f = 
= 
1240 x 
= 1428 Hz .
Answer:
14.8 kg
Explanation:
We are given that




We have to find the mass of the pulley.
According to question



Moment of inertia of pulley=

Where 



Hence, the mass of the pulley=14.8 kg