Q 11 :

A particle moves according to the law x=acosπt2. The distance covered by it in the time interval between t=0 to t=3 sec is

  • 2a

     

  • 3a

     

  • 4a

     

  • a

     

(2)

T = 4 sec, Body starts at extreme position and ends at mean position as shown.



Q 12 :

Time period of a particle executing SHM is 16 s. At time t=2s, it crosses the mean position its amplitude of motion is 322πm. Its velocity at t=4s is

  • 1 ms-1

     

  • 2 ms-1

     

  • 4 ms-1

     

  • 8 ms-1

     

(3)

For SHM,  x=Asinωt=Asin(2πtT),    v=ωA2-x2

When t=4 s, time taken by the particle to travel from the mean position to the given position=4-2=2 s

x=Asin(2πtT)=Asin(2π×216)=A2

v=ωA2-x2

v=ωA2-A22=ωA2

ω=2πT=2π16=π8

∴  v=πA82



Q 13 :

The displacement of simple harmonic oscillator after 3 seconds starting from its mean position is equal to half of its amplitude. The time period of harmonic motion is:

  • 6s

     

  • 8s

     

  • 12s

     

  • 36s

     

(4)

Time taken by the harmonic oscillator to move from mean position to half of the amplitude is T12

so, T12=3

T=36 sec



Q 14 :

The equation of motion of a particle is given by x=asin(50t+π3) cm. The particle will come to rest at time t1 and it will have zero acceleration at time t2. The t1 and t2 respectively are ______.                   [2026]

  • π300s, π75s

     

  • π75s, π300s

     

  • π300s, π25s

     

  • π50s, π100s

     

(1)

Phase of the motion of particle is as follows:

[IMAGE 40]

v=0, when particle cross A.

∴   t1=π6ω=π300

a=0, when particle cross B.

∴  t2=2π3ω=π75



Q 15 :

Match List-I with List-II.                  [2026]

  List-I   List-II
A. sin2ωt I. Periodic with time period T=πω but not simple harmonic motion (SHM)
B. sin3(2ωt) II. Periodic with time period T=2πω but not SHM
C. sin(ωt)+cos(πωt) III. Periodic with time period T=πω and SHM
D. cosωt+cos2ωt IV. Non-periodic

 

Choose the correct answer from the options given below.

  • A-III, B-I, C-IV, D-II

     

  • A-II, B-I, C-III, D-IV

     

  • A-III, B-II, C-IV, D-I

     

  • A-II, B-I, C-IV, D-III

     

(1)

(A)  sin2ωt=12-12cos2ωt, it represents SHM motion having period T=πω

(B)  sin32ωt=34sin2ωt-14sin6ωt, the common period πω but not SHM.

(C)  sinωt+cosπωt→no common period hence it is a nonperiodic function

(D)  cosωt+cos2ωt common period 2πω but it do not represent SHM.



Q 16 :

A particle is executing simple harmonic motion. Its amplitude is A and time period is 5 sec. The time required by it to move from x=A to x=A2 is _________ sec.        [2026]

  • 14

     

  • 54

     

  • 58

     

  • 38

     

(3)

[IMAGE 41]

x=0⇒Phase ϕ=0°

x=A2⇒Phase ϕ=π4

∴  phase covered Δϕ=π4

time t=Phaseω=π4ω=π4×T2π=T8

The time required by it to move from x=A to x=A2,

t'=T4-T8=T8=58 s



Q 17 :

The velocity of a particle executing simple harmonic motion along x-axis is described as v2=50-x2, where x represents displacement. If the time period of motion is x7s,the value of x is ______.                  [2026]



(44)

Given velocity of a particle, v2=50-x2

By comparing this to the standard equation

v2=ω2A2-ω2x2

∴  ω2=1⇒ω=1

Time period T=2πω=2π1=2π sec

Now compare it with x7=2π

⇒x=2×227×7=44