MyQuestionIcon

1

You visited us 1 times! Enjoying our articles? Unlock Full Access!

Velocity(Speed with Direction)

If a car cove...

Question

If a car covers $\frac{2}{5^{t h}}$ of the total distance with $v_{1}$ speed and $\frac{3}{5^{t h}}$ distance with $v_{2}$ then average speed:

A

\frac{1}{2} \sqrt{v_{1} v_{2}}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

B

\frac{v_{1} + v_{2}}{2}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

C

\frac{2 v_{1} v_{2}}{v_{1} + v_{2}}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

D

\frac{5 v_{1} v_{2}}{3 v_{1} + 2 v_{2}}

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Open in App

Solution

The correct option is D $\frac{5 v_{1} v_{2}}{3 v_{1} + 2 v_{2}}$
Time taken to cover $\frac{2}{5} t h$ distance: $t_{1} = \frac{2}{5} \frac{s}{v_{1}} = \frac{d i s t a n c e}{v e l o c i t y}$ where s is total distance
Time taken to cover $\frac{3}{5} t h$ distance: $t_{1} = \frac{3}{5} \frac{s}{v_{2}}$
Average speed $= \frac{t o t a l d i s t a n c e}{t o t a l t i m e}$
$V_{m g} = \frac{s}{t_{1} + t_{2}}$
$= \frac{s}{\frac{2 s}{5 v_{1}} + \frac{3 s}{5 v_{2}}}$
$= \frac{5 v_{1} v_{2} s}{s (2 v_{2} s + 3 v_{1} s)}$
$\frac{5 v_{1} v_{2}}{3 v_{1} + 2 v_{2}}$

Suggest Corrections

thumbs-up

4

Similar questions

Q. If a car covers

\frac{2}{5^{t h}}

of the total distance with

v_{1}

\frac{3}{5^{t h}}

v_{2}

then average speed is

If a car covers 2/5th of the total distance with v₁speed and 3/5th of the total distance with v₂ speed, then average speed of the car is

Q. A person completes half of his journey with speed

v_{1}

and rest half with speed

v_{2}

. The average speed (

v_{a v g})

of the person is

Q. The correct match is:

List - I	List - II
a) A body covers first half of distance with a speed $V_{1}$ and second half of distance with a speed $V_{2}$	e) Average velocity is $\sqrt{\frac{g h}{2}}$
b) A body covers first half of the time with a speed $V_{1}$ and second half of the time with a speed $V_{2}$	f) Average speed is $\frac{v_{1} + v_{2}}{2}$
c) A body is projected vertically up from ground with certain velocity.Considering its total motion,	g) Average speed is $\frac{2 V_{1} V_{2}}{V_{1} + V_{2}}$
d) A body freely is released from a height h	h) Average velocity is zero

Q. A person moves a certain distance in a certain time. If 1/3 of the distance is covered in 2/3 of the time with speed

V_{1}

and rest of the 2/3 distance in 1/3 of the time with speed

V_{2}

V_{1} / V_{2}

Join BYJU'S Learning Program

similar_icon

Related Videos

lock

Time, Average Speed and Velocity

PHYSICS

Watch in App

explore_more_icon

Explore more

Velocity(Speed with Direction)

Standard IX Physics

Join BYJU'S Learning Program

CrossIcon