Acceleration

• object accelerates when velocity changes

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Definition

acceleration is the rate of change of velocity per unit time. #PhysicsDefinitions

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Object undergoes acceleration when:

• speed or direction changes
• both its speed and direction change

SI unit: $m/s^2$

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Formula $Acceleration=\frac{changeofvelocity}{timetaken}$ $uniformacceleration,a=\frac{\Delta v}{\Delta t}=\frac{v-u}{t_v-t_u}$ change v = change in velocity (m/s) change t = time interval between $t_v$ and $t_u$ (s) V = final velocity U = initial velocity $t_v$ = time at which object is at final velocity (s) $t_u$ = time at which object is at initial velocity

Important

reformulation: $v=u+at$

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Acceleration ⇒ VECTOR ⇒ can be negative

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Uniform acceleration

• change (increase/decrease) in velocity of object for every unit of time = same
• Object undergoes constant/uniform acceleration

Definition

Uniform acceleration is the constant rate of change of velocity #PhysicsDefinitions

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Non uniform acceleration:

• object undergoes non uniform acceleration if change in velocity for every unit of time is NOT the same

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key words:

• increases with increasing rate
• increases with decreasing rate
• same phrasing for decrease.

Important

if the qn says deceleration you can give raw value. if it says acceleration and the object is decreasing, then must put down a (-)