SATHEE: Laws Of Motion Question 258

Laws Of Motion Question 258

Question: The velocity of a body at time t = 0 is $10 \sqrt{2}$ m/s in the north-east direction and it is moving with an acceleration of 2 m/s2 directed towards the south.The magnitude and direction of the velocity of the body after 5 sec will be [AMU (Engg.) 1999]

Options:

A) 10 m/s, towards east

B) 10 m/s, towards north

C) 10 m/s, towards south

D) 10 m/s, towards north-east

Show Answer

Answer:

Correct Answer: A

Solution:

$\vec{v} = \vec{u} + \vec{a} t$

$v = \sqrt{u^{2} + a^{2} t^{2} + 2 u a t \cos θ}$

$v = \sqrt{200 + 100 + 2 \times 10 \sqrt{2} \times 10 \times \cos 135}$

$= 10 m / s$

$\tan α = \frac{a t \sin θ}{u + a t \cos θ} \frac{10 \sin 135}{10 \sqrt{2} + 10 \cos 135} = 1$ $α = 45^{\circ}$ i.e. resultant velocity is 10 m/s towards East.

Laws Of Motion Question 258

Question: The velocity of a body at time t = 0 is $10 \sqrt{2}$ m/s in the north-east direction and it is moving with an acceleration of 2 m/s2 directed towards the south.The magnitude and direction of the velocity of the body after 5 sec will be [AMU (Engg.) 1999]

Options:

Answer:

Solution:

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Laws Of Motion Question 258

Question: The velocity of a body at time t = 0 is 102 m/s in the north-east direction and it is moving with an acceleration of 2 m/s2 directed towards the south.The magnitude and direction of the velocity of the body after 5 sec will be [AMU (Engg.) 1999]

Options:

Answer:

Solution:

Engineering Preparation

Medical Preparation

NCERT Books & Solutions

Important Resources

Other Resources

Syllabus

Test Platform

Sample Mock Test

Mentorship

NCERT Exercise Video Solution

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Question: The velocity of a body at time t = 0 is $10 \sqrt{2}$ m/s in the north-east direction and it is moving with an acceleration of 2 m/s2 directed towards the south.The magnitude and direction of the velocity of the body after 5 sec will be [AMU (Engg.) 1999]