Arc measurement with 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?

Given the lease terms below, what monthly lease payment can you expect on this vehicle? terms: •length of lease: 60 months •msrp of the car: $28,500 •purchase value of the car after lease: $12,900 •down payment: $1900 •lease factor: 0.0005 •security deposit: $375 •aquisition fee: $300 a.$232.50 b.$279.99 c.$227.50 d.$248.08

What is the approximate difference in tenths between √12 and √15?