27.9 idkkkk look it up on photomath
Answer:
Explanation:
Average velocity = Displacement/Time
ΔS = -10+6
ΔS = -4m
Given tme = 30s
Average velocity = -4/30
Average velocity = -0.13m/s
Average speed = Distance/Time
Total distance covered = 10m+6m
Total distance covered = 16m
Average speed = 16/30
Average speed = 0.53m/s
Answer:
The angle wires have to be placed to experience full force is such that the angle between the direction of current flow and the direction of the magnetic field is 90°
Explanation:
The direction of the force acting on a conductor through which a charge flows is given by Flemings Left Hand Rule which states that the direction of the force acting on a conductor carrying a current of charge is perpendicular to both the direction in which the current is flowing and the direction of the magnetic field
Therefore, wires carrying flowing charges has to be placed such that the direction of charge (current) flow is perpendicular (at 90°) to an existing magnetic field to experience (maximum) full force
Answer: 
Explanation:
Given
The frequency of the source is 
Change in frequency is 
Speed of sound 
Suppose
is the velocity of the observer
Doppler frequency is given by

Here, the source is at rest
While approaching source, frequency is

While leaving, frequency is

The difference in the frequency is
