Question

a bus is moving with a velocity of 40 ms-1 second a force of 1000 newton is applied and it comes to rest in 5 seconds calculate the retardation and mass of the bus and change in momentum brainly???
please answer asap ​

Answer 1

Explanation:

As per the provided information in the given question, we have :

• Initial velocity (u) = 40 m/s
• Force (F) = 1000 N
• Final velocity (v) = 0 (as it comes to rest)
• Time taken (t) = 5 seconds

We are asked to calculate,

• Retardation
• Mass of the bus (m)
• Change in momentum

Calculating the retardation :

In order to calculate the retardation, firstly we need to find the acceleration. As we know that,

$\longmapsto\bf { a = \dfrac{v-u}{t} }$

• v denotes final velocity
• u denotes initial velocity
• a denotes acceleration
• t denotes time

$\longmapsto\rm { a = \dfrac{0-40}{5} }$

$\longmapsto\rm { a = \dfrac{-40}{5} }$

$\longmapsto\bf { a = -8\; ms^{-2}}$

As the acceleration of the bus is -8 m/s², so the retardation of the car will be 8 m/s².

$\longmapsto\bf { Retardation = 8\; ms^{-2}}$

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Calculating the mass of the bus:

As we know that,

$\longmapsto\bf { F = ma }$

• F denotes force
• m denotes mass
• a denotes acceleration

$\longmapsto\rm { 1000 = m \times (-8) }$

$\longmapsto\rm { \dfrac{1000}{-8} = m }$

$\longmapsto\rm { -125 = m }$

As the mass can't be considered negative, so,

$\longmapsto\bf { 125 \; kg = m }$

Therefore, mass of the bus is 125 kg.

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Calculating change in momentum :

$\longmapsto\bf { \Delta p = mv - mu}$

• ∆p denotes change in momentum
• mv denotes final momentum
• mu denotes initial momentum

$\longmapsto\rm { \Delta p = 125(0) - 125(40) \; kg.ms^{-1}}$

$\longmapsto\bf { \Delta p =0 - 5000 \; kg.ms^{-1}}$

Therefore, change is momentum is -5000 kg.m/s.