v = speed of the source of sound or the train towards the listener or switchman = 40 m/s
V = actual speed of sound = 340 m/s
f = actual frequency of sound as emitted from source or the train = 1000 Hz
f' = frequency as observed by the listener or by switchman = ?
Using Doppler's law , frequency observed by a listener from a source moving towards it is given as
f' = V f /(V - v)
inserting the values
f' = 340 x 1000 /(340 - 40)
f' = 340 x 1000/300
Answer:
2 m
Explanation:
The displacement of any body is the shortest distance in an object's path between its initial and final point.
The ball would travel 3 m from the point of throwing then fall down 5 m to the ground. The total distance traveled is 7 m.
The displacement of the ball will be the distance from the point of throwing to the ground i.e., 2 m as it is the shortest distance between the initial and final point of the ball's journey.
Answer:
The shortest distance is 
Explanation:
The free body diagram of this question is shown on the first uploaded image
From the question we are told that
The speed of the bicycle is 
The distance between the axial is 
The mass center of the cyclist and the bicycle is 
behind the front axle
The mass center of the cyclist and the bicycle is 
above the ground
For the bicycle not to be thrown over the
Momentum about the back wheel must be zero so
=> 
=> 
Here 
So 
Apply the equation of motion to this motion we have
Where 
and 
since the bicycle is coming to a stop
=>
Answer:
0.8 N
Explanation:
From coulomb's law,
Formula:
F = kqq'/r²........................ Equation 1
Where F = Force of repulsion, k = coulomb's constant, q = first positive charge, q' = second positive charge, r = distance between the charge.
Given: q = 20 μC = 20×10⁻⁶ C, q' = 100 μC = 100×10⁻⁶ C, r = 150 cm = 1.5 m.
Constant: k = 9×10⁹ Nm²/C²
Substitute these values into equation 1
F = (20×10⁻⁶ )( 100×10⁻⁶)(9×10⁹)/1.5²
F = 1800×10⁻³/2.25
F = 1.8/2.25
F = 0.8 N
