What are the pros and cons of fit lines and equations?​

Astuntman jumping off a 20-m-high building is modeled by the equation h=20-5t^2, where t is the same in seconds. a high-speed camera is ready to film him between 15m and 10m above the ground. for which interval of time should the camera film him?

Emily convinced her mom to buy a giant box of her favorite cereal. her mom doesn't think the box will fit on their shelf. the volume of the box is 1000 cm^3 . the base of the box is 25 cm by 10 cm

Jenny made a scale drawing of a city. the scale she used was 5 inches = 1 yard. what is the scale factor of the drawing?