A bullet is shot vertically downwards with an initial velocity of 100 m / s from a certain height. Within 10s, the bullet reaches the ground and…

A bullet is shot vertically downwards with an initial velocity of $\displaystyle 100 \mathrm{~m} / \mathrm{s}$ from a certain height. Within 10s, the bullet reaches the ground and instantaneously comes to rest due to the perfectly inelastic collision. The velocity-time curve for total time $\displaystyle \mathrm{t}=20 \mathrm{~s}$ will be: $\displaystyle \left(\right.$ Take $\displaystyle \left.\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^2\right)$.