Answer:

Explanation:
Current is the rate of flow of charge.



Power is the rate work done given by dividing work done by unit time. It is measured in watts equivalent to J/s.
In this case the force by the student is mg = 490 N (taking g as 9.8m/s²)
Work done is given by force × distance,
Therefore, Power =(force × distance)/ time, but velocity/speed =distance/time
Thus, Power = force × speed/velocity
= 490 N × 1.25
= 612.5 J/S (Watts)
Hence, power will be 612.5 Watts.
Answer:
100cm
Explanation:
Since the eyes are 6 cm below the top of her head, the point of incidence of the ray must be
200cm-3cm=197cm
Since the eyes are 194 cm from her feet, the point of incidence of this ray must be
194cm/2=97cm
So the lower edge of the mirror must be 97 cm from the ground and the vertical dimension of the mirror must be 197 cm - 97 cm = 100 cm, which is half the height of the person.