SATHEE: Kinematics Question 171

Kinematics Question 171

Question: A projectile is fired vertically upwards with an initial velocity $u$ . After an interval of T seconds, a second projectile is fired vertically upwards, also with initial velocity $u$ .

Options:

A) They meet at time $t = \frac{u}{g}$ and at a height $\frac{u^{2}}{2 g} + \frac{g T^{2}}{8}$

B) They meet at time $t = \frac{u}{g} + \frac{T}{2}$ and at a height $\frac{u^{2}}{2 g} + \frac{g T^{2}}{8}$

C) They meet at time $t = \frac{u}{g} + \frac{T}{2}$ and at a height $\frac{u^{2}}{2 g} - \frac{g T^{2}}{8}$

D) They never meet

Show Answer

Answer:

Correct Answer: C

Solution:

[c] For first projectile, $h_{1} = u t - \frac{1}{2} g t^{2}$ For second projectile,

$h_{2} = u (t - T) - \frac{1}{2} g {(t - T)}^{2}$

When both meet i.e. $h_{1}$ = $h_{2}$ : $u t - \frac{1}{2} g t^{2} = u (t - T) - \frac{1}{2} g {(t - T)}^{2}$
$\Rightarrow u T + \frac{1}{2} g T^{2} = g t T \Rightarrow t = \frac{u}{g} + \frac{T}{2}$

And $h_{1} = u (\frac{u}{g} + \frac{T}{2}) - \frac{1}{2} g {(\frac{u}{2} + \frac{T}{2})}^{2} = \frac{u^{2}}{2 g} - \frac{g T^{2}}{8}$

Kinematics Question 171

Question: A projectile is fired vertically upwards with an initial velocity $u$ . After an interval of T seconds, a second projectile is fired vertically upwards, also with initial velocity $u$ .

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

Kinematics Question 171

Question: A projectile is fired vertically upwards with an initial velocity u . After an interval of T seconds, a second projectile is fired vertically upwards, also with initial velocity u .

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: A projectile is fired vertically upwards with an initial velocity $u$ . After an interval of T seconds, a second projectile is fired vertically upwards, also with initial velocity $u$ .