Question

A body starts to slide over a horizontal surface with an initial velocity of 0.5m/s. Due to friction it's velocity decreases at the rate of 0.05m/s^2. How much time will take for the body to stop?​

Answer 1

Answer :

›»› The time taken by body to stop = 10 sec

Given :

• Initial velocity of body (u) = 0.5 m/s
• Final velocity of body (v) = 0 m/s
• Acceleration of body (a) = -0.05 m/s²

To Find :

• Time taken by body to stop (t) = ?

Required Solution :

We can find time taken by body to stop by using the first equation of motion which says v = u + at

Here,

• v is the Final velocity in m/s.
• u is the Initial velocity in m/s.
• a is the Acceleration in m/s².
• t is the Time taken in second.

So let's find Time taken (t) !

† From first equation of motion

⇒ v = u + at

⇒ 0 = 0.5 + (-0.05)t

⇒ 0 - 0.5 = -0.05t

⇒ -0.5 = -0.05t

⇒ 0.5 = 0.05t

⇒ t = 0.05/0.5

⇒ t = 10 sec

║Hence, time taken by body to stop is 10 sec.║

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Additional Information :

★ Second equation of motion :

⪼ s = ut + ½ at²

Where,

• s is the Distance travelled in m.
• u is the Initial velocity in m/s.
• a is the Acceleration in m/s².

★ Third equation of motion :

⪼ v² = u² + 2as

Where,

• v is the Final velocity in m/s.
• u is the Initial velocity in m/s.
• a is the Acceleration in m/s².
• s is the Distance travelled in m.