public static double selectVelocity() {
		double velocity;
		while (true) {
			try {
				final String velocityString = getStringFromUser("Initial velocity");
				velocity = Double.parseDouble(velocityString);
				break;
			} catch (final Exception e) {
				System.err.println("The velocity was not a number! Try again.");
				continue;
			}
		}
		return velocity;
	}