Parametric equations in modelling Quiz

1. A ball has $y=20t-5t^2$. When does it land?

• A. $2$ s
• B. $4$ s
• C. $5$ s
• D. $20$ s

2. A ball has $x=8t$ and lands at $t=3$. How far does it travel horizontally?

• A. $24$
• B. $11$
• C. $8$
• D. $2.67$

3. A pod has $y=15-12\cos(0.5t)$. What is its least height?

• A. $15$
• B. $27$
• C. $12$
• D. $3$

4. For $y=15-12\cos(0.5t)$, what is the period of the motion?

• A. $\pi$
• B. $0.5\pi$
• C. $4\pi$
• D. $2\pi$

5. Paths of two objects cross. What must be checked for a collision?

• A. Their speeds only
• B. Their times at the crossing point
• C. The gradient of each path
• D. Their starting points