Question

1. A car weighing 2400 kg and moving with a velocity of 20 m/s is stopped in 10s on applying breaks. Calculate the retardation and retarding force?

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Answer 1

Mass (m) = 2400 kg

Initial velocity (u) = 20 m/s

Final velocity (v) = 0

Time taken (t) = 10 s

$\boxed { \purple{ \rm{Retardation \: (a) = \frac{v - u}{t} }}}$

$\rm a = \frac{0 - 20}{10} \\ \rm a = \frac{ - 20}{10} \\ \rm{ \red {a = - 2 \: m {s}^{ - 2} }}$

$\boxed{ \purple{ \rm {Retardation \: Force \:(F) = ma}}}$

$\rm F = 2400 \times - 2 \\ \rm{\red{F = - 4800~N}}$

Answer 2

Given :

• Mass (m) = 2400 kg
• Initial velocity (u) = 20 m/s
• Final velocity (v) = 0 m/s
• Time (t) = 10 seconds

To find :

• The retardation

Retardation is also called negative acceleration.

According to the question,

$\star \: \boxed{\sf \red{Acceleration \: (a)= \frac{v - u}{t} }}$

Here we will consider acceleration as retardation

So,the formula will be :

$\star \: \boxed{\sf \red{Retardation = \frac{v - u}{t} }}$

$\sf{ \: \: \: \: :\implies \frac{0 - 20}{10} }$

$\sf{ \: \: \: \: :\implies \frac{ - 20}{10} }$

$\sf{ \: \: \: \: :\implies 2 \: ms {}^{ - 1} } \: \orange\bigstar$

Now we will calculate force (F) :

$\star \: \boxed{\sf \red{ F =ma }}$

Where,

F stands for Force

a stands for Acceleration

m stands for Mass

So according to the formula we put the value

$\sf { \: \: \: \: : \implies2400 \times ( - 2)}$

$\sf { \: \: \: \: : \implies-4800 \: N}\:\:\orange\bigstar$