4) A 20kg block is pushed East by a 40N force and West by a 20N force. At what rate and in which direction will it accelerate? It will not accelerate
6 m/s/s east
1 m/s/s east
4 m/s/s west

4 m/s/s west

Explanation: As learned earlier in Lesson 3 (as well as in Lesson 2), the net force is the vector sum of all the individual forces. In Lesson 2, we learned how to determine the net force if the magnitudes of all the individual forces are known. In this lesson, we will learn how to determine the acceleration of an object if the magnitudes of all the individual forces are known. The three major equations that will be useful are the equation for net force (Fnet = m•a), the equation for gravitational force (Fgrav = m•g), and the equation for frictional force (Ffrict = μ • Form).

The process of determining the acceleration of an object demands that the mass and the net force are known. If mass (m) and net force (Fnet) are known, then the acceleration is determined by the use of the equation.

a = Fnet / m

layers of the earth affect the waves and these effects are seen on instruiments such as seimometers

what is the speed of a softball that travels 20m in 2secs

speed = 20/2 = 10 m/s