SATHEE: Kinematics Question 321

Kinematics Question 321

Question: A man standing on a road hold his umbrella at 30° with the vertical to keep the rain away. He throws the umbrella and starts running at 10 km/hr. He finds that raindrops are hitting his head vertically, the speed of raindrops with respect to the road will be

Options:

A) 10 km/hr

B) 20 km/hr

C) 30 km/hr

D) 40 km/hr

Show Answer

Answer:

Correct Answer: B

Solution:

When the man is at rest w.r.t. the ground, the rain comes to him at an angle 30° with the vertical.

this it’s the direction of the velocity of raindrops with respect to the ground.

Here ${\vec{v}}_{r g} =$ velocity of rain with respect to the ground ${\vec{v}}_{m g} =$ velocity of the man with respect to the ground.

and ${\vec{v}}_{r m} =$ velocity of the rain with respect to the man,

We have ${\vec{v}}_{r g} = {\vec{v}}_{r m} + {\vec{v}}_{m g}$ ……(i) T

aking horizontal components equation (i) gives $v_{r g} \sin 30^{\circ} = v_{m g} = 10 k m / h r$ or $v_{r g} = \frac{10}{\sin 30^{\circ}} = 20 k m / h r$

Kinematics Question 321

Question: A man standing on a road hold his umbrella at 30° with the vertical to keep the rain away. He throws the umbrella and starts running at 10 km/hr. He finds that raindrops are hitting his head vertically, the speed of raindrops with respect to the road will be

Options:

Answer:

Solution:

Engineering Preparation

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NCERT Books & Solutions

Important Resources

Other Resources

Syllabus

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Sample Mock Test

Mentorship

NCERT Exercise Video Solution

Kinematics Question 321

Question: A man standing on a road hold his umbrella at 30° with the vertical to keep the rain away. He throws the umbrella and starts running at 10 km/hr. He finds that raindrops are hitting his head vertically, the speed of raindrops with respect to the road will be

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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