baseball math?

Question

If a pitcher throws a ball at 70 miles per hour, then how much time (in seconds) does it take for the ball to travel 60ft?

Answer 1

Let's see. 60 mph translates to 88 fps. So if it's going 70/60 times 88 fps, it's going 102.67 fps, so it should take 102.67fps/60' seconds to get there, or about 1.711 seconds.

Answer 2

This problem has everything to do with units conversion. The numbers will not be hard, but you have to be careful with the units.

First, we have to convert from miles/hour to feet/second. Here's how:

(70 mi/hr x 5280 ft/mi) / (60 min/hr x 60 sec/min)

Miles and miles, hours and hours, minutes and minutes all cancel, and you get

70 mi/hr = (70 x 5280) / 3600 ft/sec

You can simplify that. All the zeroes cancel, and 12 goes into both 528 and 36. If you do the cancelling, the problem becomes

70 mi/hr = (7x44)/3 ft/sec

Now we want to know how long (seconds) it takes to go 60 feet. Flip that 7 x 44 / 3 upside-down to get 3/(7x44) seconds/foot, and then just multiply by 60 feet. The "feet" units will cancel, to give you an answer of

3/(7x44) sec/ft x 60 ft = (3x60)/(7x44) sec.

4 goes into the top and bottom. I can divide out a 4 to get the answer looking like this:

(3x15)/(7x11) sec = 45/77 sec = 0.58 seconds

It takes just over a half-second for a 70 mph fastball to travel the 60 feet from the mound to the plate.

I worked this problem slowly and in detail because I thought you'd like it that way.

Answer 3

If we have 70 miles per hour, then we divide by 3600 to get how many miles in a second. Then, you have to multply that by how many feet are in a mile. Then, divide that total by 60, and divide 1 by the answer.