Final answer:
The magnification of the video on the phone is 50x, computed by dividing the actual height of the gymnast (150cm) by the height of the gymnast's image on the phone (3cm).
Step-by-step explanation:
The question asks us to calculate the magnification of the image of a gymnast when viewed on a phone. To find the magnification, we divide the actual height of the gymnast by the height of the image as shown on the phone. The actual height of a female gymnast is given as 150cm, and the image height is 3cm. The magnification is calculated as follows:
Magnification = Actual height / Image height = 150cm / 3cm = 50
Therefore, the magnification of the video on your phone is 50x.