Question

What is near-sightedness? List its two cases. Describe with ray diagram, how this

defect may be corrected by using spectacles?​

Answer 1

Explanation:

Given:

Mass, m = 5kg

Initial Velocity, u = 20m/s

Final Velocity, v = 0.20m/s

Find:

Change In Momentum

Solution:

we, know that

\underline{ \boxed{ \pink{ \sf Δ p = m(v - u)}}}

Δp=m(v−u)

where,

m = 5kg

v = 0.20m/s

u = 20m/s

So,

\sf \to Δ p = m(v - u)→Δp=m(v−u)

\sf \to Δ p = 5(0.20 - 20)→Δp=5(0.20−20)

\sf \to Δ p = 5( - 19.8)→Δp=5(−19.8)

\underline{ \boxed{ \blue{ \sf \to Δ p = - 99kg \: m/s}}}

→Δp=−99kgm/s

Hence, change in momentum of the body will be -99kg m/s

The - ve sign indicates that there is a decrease in the momentum of the body.