Motion Test

Result

Motion Test - 69

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

When a body is accelerated: (i) its velocity always changes (ii) its speed always changes (iii) its direction always changes (iv) its speed may or may not change Which of the following is correct?

A
(i) and (ii)

B
(i) and (iv)

C
(i) only

D
(ii) and (iii)

Solution
Question 2
1 / -0

A particle is moving with velocity of $$4\ ms^{-1}$$ along positive $$x-$$direction. An acceleration of $$1\ ms^{-2}$$ is aceted on the particle along negative $$x-$$direction. Find the distance traveled by the particle in $$10\ s$$.

A
$$10\ m$$

B
$$26\ m$$

C
$$16\ m$$

D
$$8\ m$$

Solution

In this case, velocity and acceleration are acting in opposite direction and velocity will be zero after some time and the particle will change its direction of motion.
Apply first equation of motion-
$$v = u + at$$
When velocity is getting zero
$$0 = 4 + (-1)t$$
$$t = 4\ sec$$
Distance travelled in $$10\ s =$$ (Distance travelled in $$4s$$)+ (Distance travelled in $$6s$$)
Apply second equation of motion-
$$s = ut + \dfrac{1}{2}at^2$$
$$\Rightarrow s = \left[4\times 4-\dfrac {1}{2}\times 1\times (4)^2 \right]+\left[0\times 6-\dfrac {1}{2}\times 1\times (6)^2 \right]$$
$$=26\ m$$
Question 3
1 / -0

Directions For Questions

A body is dropped from a balloon moving up with a velocity of $$4ms^{-1}$$ when the balloon is at a height of 120.5 m from the ground.

...view full instructions

The height of the body after 5 s from the ground is $$(g=9.8m/s^2).$$

A
8 m

B
12 m

C
18 m

D
24 m

Solution

Initial velocity will be same as balloon velocity from which it is dropped,
Considering upward direction as positive
$$u=4m/s$$ Body was going up initially with balloon with speed of $$4m/s$$
$$a=-9.8m/s^2$$ Acceleration due to gravity downwards will be taken negative.
$$t=5s$$ Initial height =$$120.5m$$
Newton Second Law of motion
$$s=ut+\dfrac{1}{2}at^2=4\times5-\dfrac{1}{2}\times9.8\times5^2$$
$$=20-122.5=-102.5m$$
This shows that the body is $$102.5 m$$ below the initial position, i.e., height of the body $$= 120.5 - 102.5 = 18 m$$
Question 4
1 / -0

The speed-time graph of a body is straight line parallel to time axis. The body has:

A
uniform acceleration

B
uniform speed

C
variable speed

D
variable acceleration

Solution

If the speed-time graph is parallel to the time axis, then this means that the body has the same speed at all the time.
Thus, speed $$=$$ constant
Hence the body has uniform speed and thus option B is correct.
Question 5
1 / -0

Two bodies , one held $$ 1 \, m $$ vertically above the other , are released simultaneously and fall freely under gravity . After $$ 2 $$ second , the relative separation of the bodies will be :

A
$$ 4.9\, m $$

B
$$ 9.8\,m $$

C
$$ 19.6\,m $$

D
$$1 \,m $$

Solution

Now, initial separation $$ = 1\,m $$
Body $$1$$:
Initial Speed $$ = 0$$
Acceleration $$ = 9.8 \,ms^{-2} $$
Time $$ = 2 $$ seconds
Now, we know that,
$$ s = ut + \dfrac{1}{2} at^2 $$
So, $$ s_1 = \dfrac{1}{2} \times 9.8 \times 4 $$
$$ s_1 = 19.6 \, m $$
Body $$2$$:
Initial Speed $$ = 0 $$
Acceleration $$ = 9.8\, ms^{-2} $$
Time $$ = 2 $$ seconds
Now, we know that,
$$ s = ut + \dfrac{1}{2} at^2 $$

So, $$ s_2 = \dfrac{1}{2} \times 9.8 \times 4 $$

$$ s_2 = 19.6 \, m $$

Since $$ s_1 = s_2 $$ so , final separation is also $$ 1\,m $$ .
Question 6
1 / -0

If we denote speed by $$S$$, distance by $$D$$ and time by $$T$$ the relationship these equation is?

A
$$S= D \times T $$

B
$$T= \frac {S}{D}$$

C
$$S = \frac {1}{T} \times D$$

D
$$ S= \frac {T}{D}$$

Solution

$$speed = \dfrac{distance}{Time}$$
Question 7
1 / -0

A bus travels 54 km in 90 minutes. The speed of the bus is?

A
0.6m/s

B
10m/s

C
5.4m/s

D
3.6 m/s

Solution

speed = distance / time
=54 * 1000 /90 * 60
=10 m/s
Question 8
1 / -0

The correct symbol to represent the speed of an object is

A
$$5m/s$$

B
$$5mp$$

C
$$5 m/ sec^{-1} $$

D
$$5 s/m$$

Solution

Velocity is rate of change of displacement with respect to time.
Velocity $$V=\dfrac DT$$
So, unit of velocity $$=\dfrac ms$$
Hence Option : A
Question 9
1 / -0

Four cars $$A, B, C$$ and $$D$$ are moving on a levelled road. Their distance versus time graphs are shown in Fig $$8.2$$. Choose the correct statement

A
Car $$A$$ is faster than car $$D$$.

B
Car $$B$$ is the slowest.

C
Car $$D$$ is faster than car $$C$$.

D
Car $$C$$ is the slowest.

Solution

Instantaneous Speed of car
$$v=\dfrac{dx}{dt}$$
$$dx=v\ dt$$
or $$x=v\ t$$ ............(1)
For faster car velocity will be more and it will cover more distance relative to others. at the same time slower car will travel less distance.
Form the above graph car be is slowest.
Option B
Question 10
1 / -0

$$18\ km\ h^{-1}$$ is equal to :

A
$$10\ ms^{-1}$$

B
$$5\ ms^{-1}$$

C
$$18\ ms^{-1}$$

D
$$1.8\ ms^{-1}$$

Solution

$$5\ ms^{-1}$$
As, $$1km=1000m$$
and $$ 1\ hour = 60\times 60\ seconds$$
Converting $$\dfrac{18 \times 1000}{60\times 60}=5\ ms^{-1}$$

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

Motion Test - 69

Result

Motion Test - 69

Score

-

Rank

-

SHARING IS CARING

Question 1

(i) and (ii)

(i) and (iv)

(i) only

(ii) and (iii)

Solution

Question 2

$$10\ m$$

$$26\ m$$

$$16\ m$$

$$8\ m$$

Solution

Question 3

8 m

12 m

18 m

24 m

Solution

Question 4

uniform acceleration

uniform speed

variable speed

variable acceleration

Solution

Question 5

$$ 4.9\, m $$

$$ 9.8\,m $$

$$ 19.6\,m $$

$$1 \,m $$

Solution

Question 6

$$S= D \times T $$

$$T= \frac {S}{D}$$

$$S = \frac {1}{T} \times D$$

$$ S= \frac {T}{D}$$

Solution

Question 7

0.6m/s

10m/s

5.4m/s

3.6 m/s

Solution

Question 8

$$5m/s$$

$$5mp$$

$$5 m/ sec^{-1} $$

$$5 s/m$$

Solution

Question 9

Car $$A$$ is faster than car $$D$$.

Car $$B$$ is the slowest.

Car $$D$$ is faster than car $$C$$.

Car $$C$$ is the slowest.

Solution

Question 10

$$10\ ms^{-1}$$

$$5\ ms^{-1}$$

$$18\ ms^{-1}$$

$$1.8\ ms^{-1}$$

Solution

User

Question Analysis

My Perfomance

Score

-

Rank

-

Results Announcement on: coming Monday

Stay Tuned: We’ll update you on your result via email or SMS.