Advanced MathHardWhen a projectile returns to the ground
Advanced Math practice question
The height of a ball t seconds after being thrown upward is given by h(t) = 40t − 5t². After how many seconds does the ball return to the ground (height 0)?
Answer: 8
Set h = 0: 40t − 5t² = 5t(8 − t) = 0, so t = 0 (launch) or t = 8. The ball lands at t = 8.
Common wrong answers
- If you answered 4
- 4 is when the ball is at its HIGHEST point, halfway through the flight.
- If you answered 40
- 40 is the initial upward speed, not a time.
- If you answered 80
- 80 is the maximum height h(4).
More Advanced Math questions
- Hard
A population of bacteria doubles every 3 hours. If it starts at 500, which function models the population P af… - Hard
How many real solutions does x² + 4x + 5 = 0 have? - Hard
A car worth $20,000 loses 15% of its value each year. What is its value after 2 years? - Hard
An investment of $1,000 grows at 6% per year, compounded annually. Which expression gives its value after t ye… - Hard
If f(x) = x² − 1 and g(x) = x + 2, what is g(f(3))? - Hard
The parabola y = x² − 8x + 12 crosses the x-axis at two points. What is the x-coordinate of the vertex?
Not affiliated with the College Board. SAT is a trademark of the College Board.