You need to repair a broken fence in your yard. The hole in your fence is around 3 meters in length and for whatever reason, the store you go to has oddly specific width 20cm wood. Each plank of wood costs $16.20, how much will it cost to repair your fence?

The correct answer is $243

Explanation:

The hole in the fence is 3 meters, this means it is necessary to buy wood that covers this distance. Now, each meter is equal to 100 centimeters, this means 3 meters is equivalent to 300 centimeters ( 100 cm in each meter x 3). Besides this, it is known each plank covers 20cm and costs $16.20. In this context, the next step is to find how many planks are needed. The process is shown below:

300 cm (total width) ÷ 20 cm (width of 1 plank) = 15 planks

This means 15 planks are needed. Finally, fin the total cost

15 planks x $16.20 (cost of 1 plan) = $243

here we know that ball will drop down by total distance 3.2 m

so here we know that

now using kinematics

now in the same time it will cover horizontal distance of 0.75 m

so speed of the ball will be