Question

A 30kg boulder was initially moving at a velocity of 10 m/s , in order to stop it 10N of constant retarding force is applied on it . After how long will the boulder Stop ?​

Answer 1

Answer:

QᏌᎬᏚᎢᏆᎾN

A 30kg boulder was initially moving at a velocity of 10 m/s , in order to stop it 10N of constant retarding force is applied on it . After how long will the boulder Stop ?

ᎪNᏚᏔᎬᎡ

${\mathfrak{\underline{\purple{\:\:\: Given:-\:\:\:}}}}$

$\:\:\:\:\bullet\:\:\:\sf{Mass \ of \ boulder = 30 \:kg}$

$\:\:\:\:\bullet\:\:\:\sf{Initial\: velocity= 10\:m/s}$

$\:\:\:\:\bullet\:\:\:\sf{Final\: velocity= 0\:m/s}$

$\:\:\:\:\bullet\:\:\:\sf{Retarding \ force = -10N}$

${\mathfrak{\underline{\purple{\:\:\:To \:Find:-\:\:\:}}}}$

$\:\:\:\:\bullet\:\:\:\textsf{After how long will the boulder stop ?}$

${\mathfrak{\underline{\purple{\:\:\: Solution:-\:\:\:}}}}$

☯ By using F = ma

$\dashrightarrow\:\: \sf{ Force = mass \times acceleration}$

$\dashrightarrow\:\: \sf{-10=30\times a}$

$\dashrightarrow\:\: \sf{-10=30a}$

$\dashrightarrow\:\: \sf{a = -\dfrac{1}{3}m/s^{2}}$

☯ Now, using 1st equation of motion:-

$\dashrightarrow\:\: \sf{v = u +at}$

$\dashrightarrow\:\: \sf{0= 10-\dfrac{t}{3}}$

$\dashrightarrow\:\: {\boxed{\bf{t = 30\:s}}}$

Answer 2

QᏌᎬᏚᎢᏆᎾN

A 30kg boulder was initially moving at a velocity of 10 m/s , in order to stop it 10N of constant retarding force is applied on it . After how long will the boulder Stop ?

ᎪNᏚᏔᎬᎡ

Answer:

Given, m = 30 kg.

Retarding force = -10N

u = 10 m/s

v = 0.

We know, F = ma

-10 = 30 x a

a = -1/3 ms-2

Also, v = u + at

0 = 10 – t/3

Therefore, t = -10 x (-3)

= 30 s.

HOPE IT HELPS YOU