Final answer:
The height of the first bounce is 3.6m. The height of the second bounce is 3.24m. The ball rises to a height greater than 1m after 7 bounces.
Step-by-step explanation:
(a) To calculate the height of the first rise, we can multiply the initial height by 90% (0.9) since the ball rises to 90% of the height from which it is dropped. So, the height of the first bounce is 4m × 0.9 = 3.6m.
(b) Similarly, for the second bounce, we multiply the height of the first bounce (3.6m) by 90% (0.9) to get the height of the second bounce: 3.6m × 0.9 = 3.24m.
(c) To determine how many bounces result in a height greater than 1m, we can set up an inequality. Each bounce is 90% of the previous bounce, so we can represent the height after n bounces as 4m × (0.9)ⁿ. We want this height to be greater than 1m, so we set up the inequality: 4m × (0.9)ⁿ > 1m. Solving for n, we find that n > 7.
Therefore, the ball rises to a height greater than 1m after 7 bounces.