Question

If the wavelength of the wave is increased to 10 m while maintaining the speed at 600 m/s, the frequency will decrease. This is because frequency and wavelength are inversely related when speed is constant, meaning as the wavelength increases, the frequency must decrease to keep the wave speed unchanged.
make it sound as an 8th grader

Answer 1

If we make the wavelength of a wave longer, say to 10 meters, while keeping the speed at 600 meters per second, the frequency will go down. This is because frequency and wavelength are connected in a special way: when the speed of the wave stays the same, if the wavelength gets bigger, the frequency has to get smaller. So, in this case, as we increase the wavelength, the frequency decreases to keep the wave moving at the same speed.