Question

<br/>$\large{\green{\boxed{\bold{\blue{\: question:}}}}}$<br/>
a constant retardation force of 50 N is applied to a body of mass 30 kg moving initially with a speed of 18 m/s .How long does the body take to come to a hault?​

Answer 1

$\huge{\underline{\mathfrak{\green{Answer}}}}$

$\large{\star{\gray{\sf{Given}}}}$

• Force (f) = 50 N

• Mass of object (m) = 30 kg

• Initial Velocity (v) = 18 m/s

$\rule{200}{2}$

$\large{\star{\gray{\sf{To \: Find}}}}$

We have to find the time taken by object.

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$\large{\star{\gray{\sf{Solution}}}}$

We know that

$\Large{\star{\boxed{\boxed{\purple{\sf{Retardation = \frac{Force}{Mass}}}}}}}$

______________[Put Values]

$\sf{→Retardation = \frac{50}{30}} \\ \\ \sf{→Retardation = 1.667 \: ms^{-2}}$

Since, there is retardation so a will be negative.

$\large{\star{\boxed{\boxed{\orange{\sf{Retardation (a) = -1.667 \: ms^{-2}}}}}}}$

$\rule{200}{2}$

Now, We are using first equation of motion.

$\Large{\star{\boxed{\boxed{\purple{\sf{v = u + at}}}}}}$

______________[Put Values]

$\sf{→0 = 18 + (-1.667)t} \\ \\ \sf{→-18 = (-1.667)t} \\ \\ \sf{→t = \frac{-18}{-1.667}} \\ \\ \sf{→t = 7.97}$

$\large{\star{\boxed{\boxed{\orange{\sf{Time \: taken = 7.97 \: seconds}}}}}}$