f' = frequency observed by the police car after sound reflected from the vehicle and comes back to police car = 1250 Hz
f = frequency emitted by the police car = 1200 Hz
V = speed of sound = 340 m/s
v = speed of vehicle = ?
frequency observed by the police car is given as
f' = f (V + v)/(V - v)
inserting the values in the above equation
1250 = 1200 (340 + v)/(340 - v)
v = 6.9 m/s
x=gt^2/2=>t^2=2x/g=30/9.81=3.05=>t=sqrt(3.05)=1.8 s
Answer:
1 . rays should passs through correct center or points(i.e. optic center or focus)
2.your line representing rays should be straight and u should tell the nature of image
Explanation:
Answer:
Let f be force of friction on the blocks kept on inclined plane. T be tension in the string
For motion of block on the inclined plane in upward direction
T - m₁gsin40 - f = m₁a
f = μ m₁gcos40
For motion of hanging block on in downward direction
m₂g - T = m₂ a
Adding to cancel T
m₂g - - m₁gsin40 - μ m₁gcos40 = a ( m₁+m₂ )
a = g (m₂ - - m₁sin40 - μ m₁cos40) / ( m₁+m₂ )
Putting the values
a = 9.8 ( 4.75 - 2.12-1.045) / 7.6
2.04 m s⁻²
M₂ will go down and M₁ will go up with acceleration .
Explanation:
