Whenever I get a question asking about an object being thrown into the air or falling, the equation for the parabola always has a value of -16t^2 as the first term. Is -16 the universal 'a' constant in a quadratic equation dealing with gravity? Or is this just me?

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