Question

A 21) A stone dropped from a height keeps on increasing in speed. Every second its speed increases by 10 metres per second. How much distance will the stone fall between 1.5 and 2.5 seconds, after being dropped with zero speed? Use the idea of average speed.
A) 5 m
b) 10 m
c) 20m
d) 40 m

do it by average speed​

Answer 1

Answer:

c.20m

Step-by-step explanation:

using Newton's equation.

v=u+at

v=0+10m/s²×1.5s

v=15m/s²

v=u+at

v=0+10m/s²+2.5s

v=25m/s

average velocity

(25m/s+15m/s)/2

v=20m/s

using 4th equation of Newton

v²=u²+2aS

(20m/s)²=0m/s+2×10m/s×S

400m²/s²=20m/s×S

(400m²/s²)÷20m/s=S

S=20m