Acceleration: Formula, Definitions, SI Unit, Questions & More

Check definition, SI unit and formula for acceleration. Acceleration is one of the most important topics of Physics and questions based on this topic are often asked in school and competitive exams. Clear understanding and knowledge of its formula is important to solve many types of problems. Here we have also provided some questions and numerical problems based on acceleration.  

Definition of Acceleration:

Acceleration is the rate of change of velocity with respect to time. 

Formula for Acceleration:

Magnitude of acceleration is given by  the formula

a = (change in velocity)/time taken or a = (v - u)/t

Here, 

a = magnitude of acceleration, 

v = final velocity of the object, 

u = initial velocity of the object, 

t = time taken

SI Unit of Acceleration:

Acceleration is a vector quantity and its SI unit is m/s2.

Equation of  Motion with Constant Acceleration:

Knowledge of 3 important equation of motion is also important:

v = u + at

v2 = u2 + 2 as

s = ut + ½ (at2) 

Here, s is displacement and rest symbols have their usual meanings.

Questions Based On Acceleration: 

Question: What is the SI unit of acceleration?

Answer: It’s m/s2.

Question: Is acceleration a scalar or vector quantity?

Answer: Acceleration is a vector quantity.

Question: What is the SI unit of acceleration?

Problem 1: A bike accelerates from 10 m/s to 5 m/s in 5 s. What is its acceleration?

Answer:

Given,

Initial Velocity, u = 10  m/s,

Final Velocity, v = 5 m/s,

Time taken, t = 5s

So, acceleration = (v - u)/t = (5 - 10)/5 = - 1 m/s2

Here, a negative sign shows retardation or speed is decreasing.

Also Check:

Escape Velocity: Formula, Definition, Questions & More