Question

A ball is thrown upward at a speed of 28 meter per second. What is the speed of ball one second before reaching maximum height? (Given that $g = 10$ meter per second²)}

• A. 10 meter per second
• B. 1 meter per second
• C. 2 meter per second
• D. 18 meter per second

Hint:

The speed $t$ seconds before/after the peak of a vertical throw is always $g \times t$.

Answer 1

The Correct Option is A

Step 1: Concept
At maximum height, the instantaneous velocity is zero.
Step 2: Analysis
We need the speed 1 second before the speed becomes 0.
Step 3: Calculation
Using $v = u + at$ for the final second of the ascent: Final velocity (at max height) = 0. $0 = v_{target} - g(t)$ $0 = v_{target} - 10(1)$. $v_{target} = 10$ m/s.
Step 4: Conclusion
The speed 1 second before maximum height is 10 m/s.
Final Answer:(A)