Answer:
"Non-uniform velocity" occurs when<em> an object changes its velocity </em>upon motion. This happens when the object either accelerates or decelerates <em>(negative acceleration)</em> in its speed or changes its direction.
Explanation:
"Velocity" refers to<em> speed with a specific direction. </em>
If the velocity is uniform, there's<u> no change in speed and direction</u>. However, if changes occur on either the speed, direction or both, then <em>the velocity becomes </em><u><em>variable or non-uniform.</em></u>
For example, when it comes to a moving car, it is said to be in non-uniform velocity if <em>the distances covered is unequal in relation to the equal intervals of time.</em>
The correct answer to the question is : C) The horizontal momentum and the vertical momentum are both conserved.
EXPLANATION :
Before coming into any conclusion, first we have to understand the law of conservation of momentum.
As per the law of conservation of momentum, the total linear as well as angular momentum of an isolated system is always conserved . The law of conservation of energy is a universal fact.
Hence, during any type of collision, the total momentum is always conserved.
Hence, the total horizontal momentum as well as total vertical momentum are always conserved during both elastic as well as inelastic collision.
<u>Answer:</u>
<em>The average speed of the car is 66.9 km/h</em>
<u>Explanation:</u>
Here distance covered with the speed <em>57 km/h=7 km </em>
distance covered with the speed of <em>81 km/h=7 km</em>
<em>Average speed is equal to the ratio of total distance to the total time.
</em>
<em>total distance= 7 + 7= 14 km </em>
<em>
</em>
<em>time taken to cover the first 7 km= 7/57 h </em>
<em>time taken to cover the second part of the journey = 7/81 h
</em>
<em>average speed =
</em>
<u><em>Shortcut:
</em></u>
<em>When equal distances are covered with different speeds average speed=2 ab/(a+b) where a and b are the variable speeds in the phases.
</em>
The directions arrow<span> is </span>always<span> going the wrong </span>way<span>.</span>