Hello : here is a solution
Answer : 4.5 × 10⁴ square inches can be washed per hour.
Step-by-step explanation :
As we are given that an area can be washed at a rate of 4,900 cm²/min. Now we have to determine the square inches can be washed per hour.
Given conversions are:
1 cm = 0.39 in and 1 hr = 60 min
As, 1 cm² = (0.39)² in² and 1 min = 1/60 hr
So, 

Now we have to determine the square inches can be washed per hour.
As, 
So, 
Therefore, 4.5 × 10⁴ square inches can be washed per hour.
Answer:
Please see attached picture for full solution.
Sorry, I'm not sure how to do Q7 :(
Answer:
The circle has an area of about 1385 square mm.
Step-by-step explanation:
Let's recall that circles have an area that can be found with the following formula:

where r is the radius of the circle.
Now, focus your eyes on the circle. We are shown that the diameter of this circle is 42 mm, but we only want the radius. Since the radius is half the diameter, the radius is 21 mm. Now, we can solve for the area of the circle.

So, to the nearest whole number, the area of the circle is 1385 square mm.
We are basically given most of what we need to calculate the height of the cannonball.
We use the formula h = –16t+ vt + s to find the height requested.
Let v = 160
Let s = 10
Let t = time in seconds
Was the value of t included? We need to know t to plug into our formula.
You know everything else except for t. Go back to your notes to search for t. Afterward, plug the value of t and everything else given above into the formula and calculate to find h.