Summary of critical formulas and important facts

Summary of critical formulas and important facts

Physics 298 – Test 1

Velocity and Acceleration

Instantaneous velocity (v) and acceleration (a) are the slopes (at a particular point) of the x and v versus t curves, respectively.

For constant acceleration (velocity) motion average and instantaneous accelerations (velocities) are equal.

One dimensional motion under constant acceleration

Free fall under the influence of (constant) gravitational acceleration is described by the above equations with a = -g

Vectors

Vector (cross) product: where the unit vector u is at right angles to a and b whose sense is given by the right hand rule.

Projectile Motion

Independent x and y motion.
Kinematic equations above represent y motion.
x motion is constant velocity motion, x = v_ixt
If projected initial velocity (v_i) is at an angle θ to horizontal then, v_ix = v_i cos θ and v_iy = v_isin θ

Uniform Circular Motion

Centripetal acceleration is given by, a = v²/R, directed towards the centre of the circle

Relative Velocity

V’ = V + V_R

Newton’s Laws of motion

1^st Law: Special case of the second law when acceleration is zero. For objects at rest or in constant velocity motion there is no net force.

3^rd Law: For every “action” force there is an equal but opposite “reaction” force. Note that the action/reaction force pairs act on different objects.

Force Laws

The weight of an object is equal to the gravitational force acting on the object. Its direction is always towards the centre of the earth.

Application of Newton’s laws via free-body diagrams.

Centripetal Force