Answer : Magnitude
Explanation :
In a value, the magnitude is represented by its units. It can be adopted by convention or by law.
Magnitude of any unit is used to measure the same kind of quantity.
For example: The unit of length which is a physical quantity is meter (m).
So, magnitude is correct answer.

Explanation:
At the top of the tree, the velocity of the pebble is purely horizontal so we can calculate it as


Answer:
16km/h
Explanation:
Vt=20km/h ---train speed
Vd=4km/h
Donas speed relative to ground is:
Vrd=Vt-Vd
Donas is moving in opposite direction of train .
Vrd=20km/h-4km/h
Vrd=16km/h
Still go straight but would obviously go up in speed!!
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