Let distance be x.
Time in going, t 1 = x/50
Time in coming, t 2 = x/40
Total time T = x/40 +x/50 = 9x/200
Average speed = total distance/ total time
=( x+x)/(9x/200)= 2x ×200/9x = 400/9 = 44.44 km/h
Answer:
A. Mass
Explanation:
Inertia is the resistance of an object to any change in its velocity. Inertia depends only on the mass of the object: the greater the mass, the larger the inertia of the object, because it will be more difficult to change the velocity of the object.
An example to better understand: assume there is a golf ball rolling with a certain speed, and a car moving with the same speed. If we want to stop the two objects, we will need a much larger force for the car, because its mass is much greater than the gold ball, so it has much more inertia than the golf ball.
<span>One astronomical unit is equal
to the average distance between the Earth and the Sun. The answer is letter B. However,
the distance between the earth and the sun varies as the earth revolves around
the sun. but recent discoveries have proven the exact distance. It is also
equal to 149, 597, 870, 700 meters and was defined by the International
Astronomical Union. </span>
