1-3 Formulas

Chapter 3 p. 76-103

Weight is the gravitational pull on an object.

Weight (N)=Mass(Kg) * Gravitational acceleration(m/s2)

F=m(a)

**Force and Weight are the same.

a=10 m/s2 Some books a=9.8 m/s2

1. What is the weight of a 100 Kg log?

 1000 N = 100 Kg (10 m/s2)

Weight = Mass(Acceleration)

Force = Mass(Acceleration)

Newton’s second Law

Force(N) = Mass (Kg) * Gravitational acceleration(m/s2)

F=m(a)

2. What is the force on a 5,000 g object on Earth?

•   Convert to Kg

•   5,000 g = 5 Kg

5 Kg (10 m/s2) = 50 N

    m(a)=F

Alterations to the equations:

Mass                Acceleration

M = Weight/a A=Weight/M

Mass            Acceleration

M = F/A   A=F/M

3. What is the Fc if the mass is 4.5 Kg , the velocity is 125 m/s and it is traveling  around a 35 m radius circle?

•   Use the proper equation

•   Fc = m(v)2

r

•   Fc=4.5 Kg(125 m/s)2

           35 m

•   Fc=2008.9 Kg.m/s2

•   Fc=2008.9 N

*Mass must be in Kg and distance must be in meters.

The following variations to the equation WILL also be used this chapter.

Mass                Velocity  

rFc = m                   rFc     =V

(v)2                                    m