Answer:
Explanation:
The velocity of plane relative to earth is given by:
As the from given data.The velocity of plane relative to air is:
According to relative motion of velocity of the air relative to earth given by:
The magnitude is given as:
The correct answer is option ( A) the ratio of their average speeds (bird 1/bird 2) is 1.0
velocity = distance / Time
Let us assume distance covered by Bird 1 = d
case 1 (Bird 1) :-
time = 6 hours
velocity(Bird1) = d/6 = 0.167*d
case 2 (Bird 2) :-
time = 12 hours
distance is twice of Bird 1 = 2d
velocity(Bird2) = 2d/12 = 0.167*d
now, velocity of Bird1/Bird2 = (0.167*d)/(0.167*d) = 1.0
So,velocity of (Bird1/Bird2) is 1.0 .
Average velocity / Average speed = Total displacement / Total distance. Remember that the numerator is less than or equal to the denominator. As a result, the ratio is always equal to or less than one. Distance traveled divided by time taken is the most commonly used formula for calculating average speed. The other formula is to add the initial and final speeds together and divide by two.
Learn more about average speeds here :-
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Answer:
Machine Efficiency
Explanation:
Efficiency is the percent of work put into a machine by the user (input work) that becomes work done by the machine (output work). The output work is always less than the input work because some of the input work is used to overcome friction. Therefore, efficiency is always less than 100 percent
8n downwards
since downwards force is greater than upwards just minus