Question

When an object is thrown vertically upward, on reaching the highest point, its value of acceleration due to gravity would be.

• A. $4.9m{s}^{-2}$
• B. $9.8m{s}^{-2}\uparrow$
• C. $9.8m{s}^{-2}\downarrow$
• D. $0m{s}^{-2}$

Answer 1

The correct option is C $9.8m{s}^{-2}\downarrow$

When you throw a ball up in the air, its speed decreases, until it momentarily stops at the very top of the ball's motion. Its acceleration is $-9.8m{s}^{-2}$ at the very top since the body is moving upward against the gravity. In other words, the acceleration due to gravity $g=9.8m{s}^{-2}\downarrow$.