Physics Crash Course NEET>Chapter 2 - Kinematics>Level 1>Q 53

EASY

NEET

IMPORTANT

Earn 100

The position vector of a particle changes with time according to the relation $\vec{r} (t) = 15 t^{2} \hat{i} + (4 - 20 t^{2}) \hat{j} .$ What is the magnitude of the acceleration at $t = 1 ?$

90.18% studentsanswered this correctly

Important Questions on Kinematics

MEDIUM

NEET

IMPORTANT

Physics Crash Course NEET>Chapter 2 - Kinematics>Level 1>Q 54

In the cube of side $a$ shown in the figure, the vector from the central point of the face $A B O D$ to the central point of the face $B E F O$ will be:
Question Image

EASY

NEET

IMPORTANT

Physics Crash Course NEET>Chapter 2 - Kinematics>Level 1>Q 55

A body is thrown vertically upwards. Which one of the following graphs correctly represents the velocity

(v)

vs time

(t)

?

EASY

NEET

IMPORTANT

Physics Crash Course NEET>Chapter 2 - Kinematics>Level 1>Q 56

An automobile, traveling at

40 km h^{- 1}

, can be stopped at a distance of

40 m

by applying brakes. If the same automobile is traveling at

80 km h^{- 1}

, the minimum stopping distance in metres is (Assume no skidding):

MEDIUM

NEET

IMPORTANT

Physics Crash Course NEET>Chapter 2 - Kinematics>Level 1>Q 57

A tennis ball is released from a height

h

and after freely falling on a wooden floor it rebounds and reaches height

h / 2

. The velocity versus height of the ball during its motion may be represented graphically by: (graphs are drawn schematically and on not to scale)

MEDIUM

NEET

IMPORTANT

Physics Crash Course NEET>Chapter 2 - Kinematics>Level 1>Q 58

The acceleration at the end of

2 s

, of a particle whose motion is represented by the equation

S = 4 t^{3} - 8 t^{2} + 5 t + 4

is ______

MEDIUM

NEET

IMPORTANT

Physics Crash Course NEET>Chapter 2 - Kinematics>Level 1>Q 59

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

NEET

IMPORTANT

Physics Crash Course NEET>Chapter 2 - Kinematics>Level 1>Q 60

A body is projected vertically upwards with a velocity

' u'

from the top of a tower. Time taken by it to reach the ground is

' n'

times the time taken by it to reach the highest point in its path. Height of the tower is

EASY

NEET

IMPORTANT

Physics Crash Course NEET>Chapter 2 - Kinematics>Level 1>Q 61

Consider the acceleration, velocity and displacement of a tennis ball as its falls to the ground and bounces back. Directions of which of these change in the process?