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MOTION IN A STRIGHT LINE

269702 If a body covers first half of its journey with uniform speed $v$ and the second half of the journey with uhiform speed $v_{2}$ , then the average speed is

1

v_{1} + v_{2}

2

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

3

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

4

V_{1} v_{2}

Explanation:

Averagespeed $= \frac{S_{1} + S_{2}}{t_{1} + t_{2}} \Rightarrow v = \frac{2 v_{1} v_{2}}{v_{1} + v_{2}}$

MOTION IN A STRIGHT LINE

269703 $A$ car is moving along a straight line, say $O P$ in figure. It moves from 0 to $P$ in $18 s$ and return from $P$ to $Q$ in $6 s$ . W hat are the average velocity and average speed of the car in going from $O$ to $P$ and back to $Q$ ?

1

10 {ms}^{- 1}, 20 {ms}^{- 1}

2

20 {ms}^{- 1}, 10 {ms}^{- 1}

3

10 {ms}^{- 1}, 10 {ms}^{- 1}

4

20 {ms}^{- 1}, 20 {ms}^{- 1}

Explanation:

$v_{avg} = \frac{total displacement}{total time} = \frac{S_{1} + S_{2}}{t_{1} + t_{2}}$

MOTION IN A STRIGHT LINE

269704 For a body moving with uniform acceleration ' $a$ ', initial and final velocities in a time interval ' $t$ ' are ' $u$ ' and ' $v$ ' respectively. Then, its average velocity in the time interval ' $t$ ' is

1

Extra \left or missing \right

2

(v - \frac{a t}{2})

3

(v - a t)

4

(u - \frac{a t}{2})

Explanation:

$v_{avg} = \frac{v + u}{2} = \frac{v + v - at}{2}$

MOTION IN A STRIGHT LINE

269721 For a train that travels from one station to another at a uniform speed of $40 {kmh}^{- 1}$ and returns to final station at speed of $60 {kmh}^{- 1}$ , then its average speed is

1

98 km / hr

2

0 km / hr

3

50 km / hr

4

48 km / hr

Explanation:

$v_{avg} = \frac{2 v_{1} v_{2}}{v_{1} + v_{2}}$

MOTION IN A STRIGHT LINE

269702 If a body covers first half of its journey with uniform speed $v$ and the second half of the journey with uhiform speed $v_{2}$ , then the average speed is

1

v_{1} + v_{2}

2

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

3

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

4

V_{1} v_{2}

Explanation:

Averagespeed $= \frac{S_{1} + S_{2}}{t_{1} + t_{2}} \Rightarrow v = \frac{2 v_{1} v_{2}}{v_{1} + v_{2}}$

MOTION IN A STRIGHT LINE

269703 $A$ car is moving along a straight line, say $O P$ in figure. It moves from 0 to $P$ in $18 s$ and return from $P$ to $Q$ in $6 s$ . W hat are the average velocity and average speed of the car in going from $O$ to $P$ and back to $Q$ ?

1

10 {ms}^{- 1}, 20 {ms}^{- 1}

2

20 {ms}^{- 1}, 10 {ms}^{- 1}

3

10 {ms}^{- 1}, 10 {ms}^{- 1}

4

20 {ms}^{- 1}, 20 {ms}^{- 1}

Explanation:

$v_{avg} = \frac{total displacement}{total time} = \frac{S_{1} + S_{2}}{t_{1} + t_{2}}$

MOTION IN A STRIGHT LINE

269704 For a body moving with uniform acceleration ' $a$ ', initial and final velocities in a time interval ' $t$ ' are ' $u$ ' and ' $v$ ' respectively. Then, its average velocity in the time interval ' $t$ ' is

1

Extra \left or missing \right

2

(v - \frac{a t}{2})

3

(v - a t)

4

(u - \frac{a t}{2})

Explanation:

$v_{avg} = \frac{v + u}{2} = \frac{v + v - at}{2}$

MOTION IN A STRIGHT LINE

269721 For a train that travels from one station to another at a uniform speed of $40 {kmh}^{- 1}$ and returns to final station at speed of $60 {kmh}^{- 1}$ , then its average speed is

1

98 km / hr

2

0 km / hr

3

50 km / hr

4

48 km / hr

Explanation:

$v_{avg} = \frac{2 v_{1} v_{2}}{v_{1} + v_{2}}$

MOTION IN A STRIGHT LINE

269702 If a body covers first half of its journey with uniform speed $v$ and the second half of the journey with uhiform speed $v_{2}$ , then the average speed is

1

v_{1} + v_{2}

2

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

3

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

4

V_{1} v_{2}

Explanation:

Averagespeed $= \frac{S_{1} + S_{2}}{t_{1} + t_{2}} \Rightarrow v = \frac{2 v_{1} v_{2}}{v_{1} + v_{2}}$

MOTION IN A STRIGHT LINE

269703 $A$ car is moving along a straight line, say $O P$ in figure. It moves from 0 to $P$ in $18 s$ and return from $P$ to $Q$ in $6 s$ . W hat are the average velocity and average speed of the car in going from $O$ to $P$ and back to $Q$ ?

1

10 {ms}^{- 1}, 20 {ms}^{- 1}

2

20 {ms}^{- 1}, 10 {ms}^{- 1}

3

10 {ms}^{- 1}, 10 {ms}^{- 1}

4

20 {ms}^{- 1}, 20 {ms}^{- 1}

Explanation:

$v_{avg} = \frac{total displacement}{total time} = \frac{S_{1} + S_{2}}{t_{1} + t_{2}}$

MOTION IN A STRIGHT LINE

269704 For a body moving with uniform acceleration ' $a$ ', initial and final velocities in a time interval ' $t$ ' are ' $u$ ' and ' $v$ ' respectively. Then, its average velocity in the time interval ' $t$ ' is

1

Extra \left or missing \right

2

(v - \frac{a t}{2})

3

(v - a t)

4

(u - \frac{a t}{2})

Explanation:

$v_{avg} = \frac{v + u}{2} = \frac{v + v - at}{2}$

MOTION IN A STRIGHT LINE

269721 For a train that travels from one station to another at a uniform speed of $40 {kmh}^{- 1}$ and returns to final station at speed of $60 {kmh}^{- 1}$ , then its average speed is

1

98 km / hr

2

0 km / hr

3

50 km / hr

4

48 km / hr

Explanation:

$v_{avg} = \frac{2 v_{1} v_{2}}{v_{1} + v_{2}}$

MOTION IN A STRIGHT LINE

269702 If a body covers first half of its journey with uniform speed $v$ and the second half of the journey with uhiform speed $v_{2}$ , then the average speed is

1

v_{1} + v_{2}

2

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

3

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

4

V_{1} v_{2}

Explanation:

Averagespeed $= \frac{S_{1} + S_{2}}{t_{1} + t_{2}} \Rightarrow v = \frac{2 v_{1} v_{2}}{v_{1} + v_{2}}$

MOTION IN A STRIGHT LINE

269703 $A$ car is moving along a straight line, say $O P$ in figure. It moves from 0 to $P$ in $18 s$ and return from $P$ to $Q$ in $6 s$ . W hat are the average velocity and average speed of the car in going from $O$ to $P$ and back to $Q$ ?

1

10 {ms}^{- 1}, 20 {ms}^{- 1}

2

20 {ms}^{- 1}, 10 {ms}^{- 1}

3

10 {ms}^{- 1}, 10 {ms}^{- 1}

4

20 {ms}^{- 1}, 20 {ms}^{- 1}

Explanation:

$v_{avg} = \frac{total displacement}{total time} = \frac{S_{1} + S_{2}}{t_{1} + t_{2}}$

MOTION IN A STRIGHT LINE

269704 For a body moving with uniform acceleration ' $a$ ', initial and final velocities in a time interval ' $t$ ' are ' $u$ ' and ' $v$ ' respectively. Then, its average velocity in the time interval ' $t$ ' is

1

Extra \left or missing \right

2

(v - \frac{a t}{2})

3

(v - a t)

4

(u - \frac{a t}{2})

Explanation:

$v_{avg} = \frac{v + u}{2} = \frac{v + v - at}{2}$

MOTION IN A STRIGHT LINE

269721 For a train that travels from one station to another at a uniform speed of $40 {kmh}^{- 1}$ and returns to final station at speed of $60 {kmh}^{- 1}$ , then its average speed is

1

98 km / hr

2

0 km / hr

3

50 km / hr

4

48 km / hr

Explanation:

$v_{avg} = \frac{2 v_{1} v_{2}}{v_{1} + v_{2}}$