Acceleration

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Acceleration

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Definition:​​

Rate of change of velocity of an object with respect to time is called acceleration.

Positive Acceleration:

  • Acceleration is a vector quantity.
  •  Its SI unit is metre per second per second square m/s2.
  •  It is denoted by a.

Formula:

acceleration = change in velocity/ time taken

 \( a= \frac{v}{t}\)

a = (vf – vi)/t

Types Of Acceleration:

Following are the three types of acceleration

If the velocity of a body increases continuously then the acceleration is said to be positive.

Negative Acceleration:

If the velocity of a body decreases continuously then the acceleration is said to be negative is called deceleration or retardation.

Uniform acceleration:

“A constant rate of change of velocity is called uniform acceleration.”

Formula:

\(a = \frac{v_f – v_i}{t}\)

Worked Examples:

“A car travelling at 30 m/s accelerates at a constant rate of 2 m/s2 for 10 seconds.

Calculate its final velocity and the distance travelled during this time.

Solution

Step 1: Write the known quantities and point out quantities to be found.

Vi = 30 m/s

a = 2 m/s^2

t = 10 s

Vf = ?

distance = ?

Step 2: Write the formula and rearrange if necessary.

Vf = Vi + at

distance = Vi*t + (1/2)at2

Step 3: Put the value in the formula and calculate.

Vf = 30 + 210 = 50 m/s

distance = 3010 + (1/2)2(102) = 350 m

The final velocity of the car is 50 m/s and it travels a distance of 350 m during the 10 seconds of acceleration.”