Mark E.
Here's an example form in HTML that could be used with the PHP implementation of the GoKart Speed Calculator:
HTML:
<!DOCTYPE html>
<html>
<head>
<title>GoKart Speed Calculator</title>
</head>
<body>
<h1>GoKart Speed Calculator</h1>
<form method="post" action="calculate.php">
<label for="gear_ratio">Gear Ratio:</label>
<input type="number" id="gear_ratio" name="gear_ratio" step="0.01" required><br>
<label for="engine_rpm">Engine RPM:</label>
<input type="number" id="engine_rpm" name="engine_rpm" required><br>
<button type="submit">Calculate</button>
</form>
</body>
</html>
This form contains two input fields for the gear ratio and engine RPM, as well as a submit button to submit the form to the PHP script. Note that each input field has a unique id attribute, which is used to associate the input with the corresponding PHP variable. Additionally, the required attribute is used to ensure that each field is filled out before the form is submitted, and the step attribute of the gear ratio input field specifies the minimum value change. The action attribute of the form specifies the URL of the PHP script that will be executed when the form is submitted.
PHP:
<?php
// Define the constants
define('WHEEL_CIRCUMFERENCE', 6.28); // in feet
define('SECONDS_PER_HOUR', 3600);
// Get the input variables from the user
$gearRatio = $_POST['gear_ratio'];
$engineRPM = $_POST['engine_rpm'];
// Calculate the wheel RPM
$wheelRPM = $engineRPM / $gearRatio;
// Calculate the kart's speed in MPH
$speed = ($wheelRPM * WHEEL_CIRCUMFERENCE * SECONDS_PER_HOUR) / (5280 * 60);
// Output the results
echo "GoKart speed: " . number_format($speed, 2) . " MPH\n";
?>