Question

A particle is moving along positive X-axis with uniform acceleration –2 ms–2. Its initial velocity is 20 ms–1. Calculate out average speed after 15 seconds ?

Answer 1

Answer:-

• Initial velocity=u=20m/s
• Acceleration=a=-2m/s^2
• Time=t=15s
• Final velocity=v=?

According to first equation of motion.

$\boxed{\sf v=u+at}$

$\\ \sf\longmapsto v=20+(-2)(15)$

$\\ \sf\longmapsto v=20+(-30)$

$\\ \sf\longmapsto v=20-30$

$\\ \sf\longmapsto v=-10m/s$