# Physics Mcqs For Test Preparation Of All Competitive Exam With Answers Each of four particles move along an x axis. Their coordinates (in meters) as functions of time
(in seconds) are given by

particle 1: x(t) = 3.5 − 2.7t3
particle 2: x(t) = 3.5 +2.7t3
particle 3: x(t) = 3.5 +2.7t2
particle 4: x(t) = 3.5 − 3.4t − 2.7t2

Which of these particles have constant acceleration?
A. All four

B. Only 1 and 2
C. Only 2 and 3
D. Only 3 and 4
E. None of them

Each of four particles move along an x axis. Their coordinates (in meters) as functions of time
(in seconds) are given by

particle 1: x(t) = 3.5 − 2.7t3
particle 2: x(t) = 3.5 +2.7t3
particle 3: x(t) = 3.5 +2.7t2
particle 4: x(t) = 3.5 − 3.4t − 2.7t2

Which of these particles is speeding up for t > 0?
A. All four
B. Only 1
C. Only 2 and 3
D. Only 2, 3, and 4
E. None of them

An object starts from rest at the origin and moves along the x axis with a constant acceleration
of 4m/s2. Its average velocity as it goes from x = 2m to x = 8m is:

A. 1m/s
B. 2m/s
C. 3m/s
D. 5m/s
E. 6m/s

Of the following situations, which one is impossible?
A. A body having velocity east and acceleration east
B. A body having velocity east and acceleration west
C. A body having zero velocity and non-zero acceleration
D. A body having constant acceleration and variable velocity
E. A body having constant velocity and variable acceleration

Throughout a time interval, while the speed of a particle increases as it moves along the x axis,
its velocity and acceleration might be:

A. positive and negative, respectively
B. negative and positive, respectively
C. negative and negative, respectively
D. negative and zero, respectively
E. positive and zero, respectively

A particle moves on the x axis. When its acceleration is positive and increasing:
A. its velocity must be positive
B. its velocity must be negative
C. it must be slowing down
D. it must be speeding up
E. none of the above must be true

The position y of a particle moving along the y axis depends on the time t according to the
equation y = at − bt2. The dimensions of the quantities a and b are respectively:

A. L2/T, L3/T2
B. L/T2, L2/T
C. L/T, L/T2
D. L3/T, T2/L
E. none of these