Question

a motorcycle of mass 180 kg running with a speed of 50 m/s is stopped in 10s on applyind brakes.Calculate the constant retaedation of the motorcycle and the retarding force exerted by the brakes.​

Answer 1

Answer:

Given :

➡️ mass of the motorcycle = 180kg

➡️ initial velocity = u = 50m/s

➡️ final velocity = v = 0m/s (as the motorcycle stopped on applying brakes )

➡️ time for the motorcycle to stop = 10s

To find :

➡️ constant retardation of the motorcycle

➡️ retarding force exerted by brakes

Solution :

according to newton's equation,

we have v = u + at

substituting the values of v,u and t, we get

0 m/s = 50m/s + a×10s

that is,(0-50)m/s = a×10s

that is, -50/10 m/(s×s) = a

that is, a = -5m/s square

That is, retardation = -(a) = -(-5m/s) = 5m/s

Hence, the constant retardation of the motorcycle while applying brakes is 5 m/s square

we know that force = mass × acceleration

that is, force due to brakes = 180×(-5) N

that is, force = -900N

that is, retarding force = -(-900N) = 900N

Hence, the retarding force due to the brakes is 900N.

Answer 2

$\huge{\underline{\tt{\red{Question-}}}}$

★ A motorcycle of mass 180 kg running with a speed of 50 m/s is stopped in 10s on applyind brakes.Calculate the constant retaedation of the motorcycle and the retarding force exerted by the brakes.

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$\bold{\underline{\tt{\purple{Given}}}}$

⭐ mass of motorcycle = 180kg

⭐ initial velocity (u) = 50m\s

⭐ Final velocity (v) = 0.

⭐ Time to stop = 10s

$\bold{\underline{\tt{\purple{To Find}}}}$

⭐ retardation (a) = ?

⭐ retarding force by brakes = ?

$\bold{\underline{\tt{\purple{Solution-}}}}$

(a) As we know that

$\implies$retardation (a) = $\dfrac{v-u}{t}$

$\implies$retardation (a) = $\dfrac{0-50}{10}$

$\implies$retardation (a) = $\cancel\dfrac{-50}{10}$

$\implies$retardation (a) = -5m\s²

(b) As we know that

$\implies$Force = mass × acceleration

$\implies$Force = 180 × -5

$\implies$Force = -900kgm\s

$\implies$Retarding force = 900kgm\s

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Extra information

★ Retardation – Change in the velocity of an object per unit time but the force acting on object is always in opposite direction

★ It is a vector quantity

★ It is always measured in negative

★The si unit is m\s²