This document provides 3 examples of physics problems involving forces and acceleration. The first example calculates acceleration given two forces acting on a 5 kg mass. The second finds the acceleration of a 2 kg block pushed by a 20 N force at a 30 degree angle. The third involves two masses, 3 kg and 5 kg, connected by a string over a pulley, and calculates the string tension, accelerations, and distances moved in one second starting from rest.

1. Chapter 3
Examples

2. Example 1
• Two forces, F1 and F2, act on a 5-kg mass. If F1
=20 N and F2 =15 N, find the acceleration in
(a) and (b) of the Figure.

3. Example 2
• A block is pushed across a horizontal surface
by the force shown. If F =20 N, = 30º and M =
2.0 kg, then the magnitude of the acceleration
(in m/s2) of the block is:

4. Example 3
• Two masses of 3 kg and 5 kg are
connected by a light string that
passes over a smooth pulley as
shown in the Figure. Determine (a)
the tension in the string, (b) the
acceleration of each mass, and (c)
the distance each mass moves in
the first second of motion if they
start from rest.