A body is thrown up which eventually comes down. Taking air drag proportional to speed into consideration, it's velocity-time (v-t) graph is best represented by

Dear studnent,

Since air drag is proportional to speed, when the particle is in upwards motion, the acceleration downwards decreases. Hence the slope of v-t curve would decrease.

When coming down, the net acceleeration downwards decreasees again as time increases and so does the slope of v-t curve.

Hence correct answer is option 2.