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Assertion: An object is at rest momentarily when it reverses the direction of its motion.

Reason: An object cannot have acceleration if the velocity of object is zero at a given instant of time

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Important Questions on Dynamics

EASY

Mathematics>Statics and Dynamics>Dynamics>Basics of Dynamics

A swimmer can swim in still water at a speed of

15 km {hr}^{- 1}

. A river is flowing at

5 km {hr}^{- 1}

. The swimmer starts from a point and swim

1 km

Upstream and then returns by swimming downstream back to original position. During this, the average speed of his/her swimming is :

EASY

Mathematics>Statics and Dynamics>Dynamics>Basics of Dynamics

A car travels in a straight line along a road. Its distance

' x'

from a stop sign is given as a function of

' t'

by the equation

x (t) = α t + β t^{3},

where

α = 2.0 m s^{- 1}, β = 0.01 m s^{- 3} .

Calculate the average velocity of the car in the time interval

t = 2.00 \sec

4.00 \sec .

EASY

Mathematics>Statics and Dynamics>Dynamics>Basics of Dynamics

A rocket starts from rest and accelerates with

g

. When speed becomes,

V_{0}

, the engine is switched off. What is the average velocity from the ground till it reaches a stop?
(

g =

acceleration due to gravity)

EASY

Mathematics>Statics and Dynamics>Dynamics>Basics of Dynamics

As shown in the figure, a particle is moving with constant speed $π m s^{- 1}$ . Considering its motion from $A$ to $B$ , the magnitude of the average velocity is:

Question Image

MEDIUM

Mathematics>Statics and Dynamics>Dynamics>Basics of Dynamics

A particle is moving such that its position coordinates

(x, y)

are

(2 m, 3 m)

at time

t = 0,

(6 m, 7 m)

at time

t = 2 s

and

(13 m, 14 m)

at time

t = 5 s

. The average velocity vector

({\vec{V}}_{a v})

from

t = 0

t = 5 s

is:

EASY

Mathematics>Statics and Dynamics>Dynamics>Basics of Dynamics

A car travels a distance of

x

with speed

v_{1}

and then same distance

x

with speed

v_{2}

in the same direction. The average speed of the car is:

EASY

Mathematics>Statics and Dynamics>Dynamics>Basics of Dynamics

A cyclist traversed half the distance of a linear track with a velocity

10 m s^{- 1} .

The remaining part of the track was covered with a velocity

v_{1}

for half the time and a velocity

v_{2}

for the other half of the time. If

v_{1} + v_{2} = 20 m s^{- 1},

then the average velocity of the cyclist during the completion of the journey through the track is

EASY

Mathematics>Statics and Dynamics>Dynamics>Basics of Dynamics

A person travels

x

distance with velocity

v_{1}

and then

x

distance with velocity

v_{2}

in the same direction. The average velocity of the person is

v

, then the relation between

v, v_{1}

and

v_{2}

will be

MEDIUM

Mathematics>Statics and Dynamics>Dynamics>Basics of Dynamics

Consider a car initially at rest, starts to move along a straight road first with acceleration

5 m s^{- 2},

then with uniform velocity and finally, decelerating at

5 m s^{- 2},

, before coming to a stop. Total time taken from start to end is

t = 25 s

. If the average velocity during that time is

72 km {hr}^{- 1},

the car moved with uniform velocity for a time of

EASY

Mathematics>Statics and Dynamics>Dynamics>Basics of Dynamics

A car moves in positive

Y

-direction with velocity

v

proportional to distance travelled

y

v (y) \propto y^{β}

, where

β

is a positive constant. The car covers a distance

L

with average velocity

<v>

proportional to

L

<v> \propto L^{1 / 3}

. The constant

β

is given as

EASY

Mathematics>Statics and Dynamics>Dynamics>Basics of Dynamics

A car moves from point A to point B at a speed of

40 km h^{- 1}

and returns at a speed of

60 km h^{- 1}

. Find its average velocity.

EASY

Mathematics>Statics and Dynamics>Dynamics>Basics of Dynamics

If work, force and time are represented by

A

B

and

C

respectively then the term

(\frac{A}{B C}) w i l l p r e s e n t

EASY

Mathematics>Statics and Dynamics>Dynamics>Basics of Dynamics

Average velocity of a particle executing SHM in one complete vibration is

EASY

Mathematics>Statics and Dynamics>Dynamics>Basics of Dynamics

If force, momentum, and displacement are represented by

A

B

and

C

respectively then the term

[\frac{A C}{B}]

will represent:

MEDIUM

Mathematics>Statics and Dynamics>Dynamics>Basics of Dynamics

Give differences between speed and velocity.

EASY

Mathematics>Statics and Dynamics>Dynamics>Basics of Dynamics

Speed measured over a measurable time interval is called average speed.

EASY

Mathematics>Statics and Dynamics>Dynamics>Basics of Dynamics

A body in motion is measured to be $- 5 m / s$ . Is it speed or velocity?

EASY

Mathematics>Statics and Dynamics>Dynamics>Basics of Dynamics

A train travels

300 km

in five hours. What is the speed of train in kilometre per hour?

MEDIUM

Mathematics>Statics and Dynamics>Dynamics>Basics of Dynamics

Give three differences between speed and velocity.

EASY

Mathematics>Statics and Dynamics>Dynamics>Basics of Dynamics

Where does the coin fall, when a passenger in a train moving with a constant speed, tosses a coin,

Assertion: An object is at rest momentarily when it reverses the direction of its motion. Reason: An object cannot have acceleration if the velocity of object is zero at a given instant of time

Important Questions on Dynamics

Learn and Prepare for any exam you want !

Assertion: An object is at rest momentarily when it reverses the direction of its motion.

Reason: An object cannot have acceleration if the velocity of object is zero at a given instant of time