1. Multi Equation Problems

2. At this point, you know a few equations… p = m * v D = m/V F = m*a s = d/t a = (v f -v i )/t F w = m*g Do any of these equations have similar parts?

3. So now we can use multiple equations in one problem…  An ice cube, with a density of.93g/cm 3, has a volume of 185cm 3. If it is thrown with a force of 9.5N, what is the acceleration at which the ice cube was thrown? What have you been given? Density =.93g/cm 3 Volume = 185cm 3 Force = 9.5N What are you looking for? Acceleration = ?  If I am searching for Acceleration, I have 2 triangles that have Acceleration. Which one would I use here? a = (vf – vi)/t F = m * a

4. So now we can use multiple equations in one problem…  An ice cube, with a density of.93g/cm 3, has a volume of 185cm 3. If it is thrown with a force of 9.5N, what is the acceleration at which the ice cube was thrown? If I am solving for acceleration, where do I get my mass from? From Density = Mass / volume Solve for mass using D=m/V, then plug into F=ma. Don’t forget to convert g (from density) to kg (from force)! (This is the only time you will ever have to convert units)

5. So now we can use multiple equations in one problem…  An ice cube, with a density of.93g/cm 3, has a volume of 185cm 3. If it is thrown with a force of 9.5N, what is the acceleration at which the ice cube was thrown?  D = m / V.93 g/cm 3 = m / 185cm 3.93 g/cm 3 * 185cm 3 = m m = 172.05g  CONVERT from grams (172.05g) to kilograms (.17205kg)  F = m * a 9.5N = 0.17205kg * a 9.5N / 0.17205kg = a  Acceleration = 55.88m/s 2