Motion in Straight Line

Definitions

Vector

A quantity that has magnitude and direction

Scalar

A quantity that has magnitude but no direction

Statics

The branch of mechanics which deals with the study of objects at rest or at equilibrium

Kinematics

The branch of mechanics which deals with study of motion of an object without considering the cause of motion

Dynamics

The branch of mechanics which deals with the study of motion of an object taking into consideration the cause of motion.

Acceleration due to gravity

the acceleration of an object in free fall that results from the influence of Earth's gravity

Path length

Total distance traversed by an object during its motion

Displacement

The shortest distance between the initial and final point of motion of an object

Speed

Distance travelled per unit time

Velocity ( 𝘷 )

Displacement of a particle per unit time

Average Velocity ( ā )

The total displacement divided by the total time interval during which the displacement occurs

Instantaneous

done in an instant; immediate

Acceleration ( 𝘢 )

The rate of change of velocity

Linear Motion

Motion along a straight line

Position graph of constant positive velocity

Constant positive slope

Kinematic equation developed based on the velocity v time graph of an object that is accelerating at a constant rate. Does not require the displacement variable to solve it.

vf = v₀ + a•t

Kinematic equation that is developed from the position vs time graph for an object accelerating at a constant rate. Does not require the final velocity variable to solve it.

∆x = v₀•t + (1/2)a•t²

Kinematic Equation that does not require the acceleration variable to solve it.

∆x = ½(vf - v₀) • t

Kinematic Equation that does not require the time variable to solve it.

vf²= v₀² + 2a•∆x

How do you find the acceleration of an object from a velocity vs. time graph?

Calculate the slope

How do represent and find the instantaneous velocity of an object that is accelerating from the position vs. time graph.

Draw a tangent line on the graph at that point, and calculate the slope of the tangent line.

Uniform acceleration

If the velocity of a body changes by equal amounts in equal intervals of time however small the time interval may be, the acceleration is said to be uniform

Stopping distance of a vehicle

When the brakes are applied to a moving vehicle, the distance moved by the vehicle before stopping without skidding

Reaction time

Time taken by a person to obverse, think and act

Relative velocity

The velocity of an body with respect to another body

Free falling body

A body which moves under the effect of gravity alone