Projectile Motion Mdcat
Projectile Motion Mdcat
      speed. On the same surface it will             height attained by the ball above
      cover a distance, when projected               the point of projection will be about
      with double the initial speed                  (a) 10 m           (b) 7.5 m
      (a) 100 m          (b) 150 m                   (c) 5 m            (d) 2.5 m
      (c) 200 m          (d) 250 m             41.   In a projectile motion, velocity at
36.   A ball is thrown upwards at an                 maximum height is
      angle of 60o to the horizontal. It             (a) u cos         (b) u cos 
      falls on the ground at a distance of                    2
      90 m. If the ball is thrown with the                 u sin 
                                                     (c)                  (d) None of these
      same initial velocity at an angle 30o,                  2
      it will fall on the ground at a          42.   If two bodies are projected at 30o
      distance of                                    and 60o respectively, with the same
      (a) 30 m           (b) 60 m                    velocity, then
      (c) 90 m           (d) 120 m                   (a) Their ranges are same
37.   Four bodies P, Q, R and S are                  (b) Their heights are same
      projected with equal velocities                (c) Their times of flight are same
      having angles of projection 15o, 30o,          (d) All of these
      45o and 60o with the horizontal          43.   A body is thrown with a velocity of
      respectively.     The body having              9.8 m/s making an angle of 30o with
      shortest range is                              the horizontal. It will hit the ground
      (a) P              (b) Q                       after a time
      (c) R              (d) S                       (a) 1.5 s            (b) 1 s
38.   For a projectile, the ratio of                 (c) 3 s              (d) 2 s
      maximum height reached to the            44.   A cricketer can throw a ball to a
      square of flight time is                       maximum horizontal distance of
      (g = 10 ms–2)                                  100 m. With the same effort, he
      (a) 5 : 4          (b) 5 : 2                   throws the ball vertically upwards.
      (c) 5 : 1          (d) 10 : 1                  The maximum height attained by
                                                     the ball is
39.   Which of the following sets of                 (a) 100 m            (b) 80 m
      factors will affect the horizontal             (c) 60 m             (d) 50 m
      distance covered by an athlete in a      45.   A cricketer can throw a ball to a
      long–jump event                                maximum horizontal distance of
      (a) Speed before he jumps and his              100 m. The speed with which he
            weight                                   throws the ball is (to the nearest
      (b) The direction in which he leaps            integer)
            and the initial speed                    (a) 30 ms–1          (b) 42ms–1
      (c) The force with which he pushes             (c) 32ms–1           (d) 35ms–1
            the ground and his speed           46.   A ball is projected with velocity Vo
      (d) None of these                              at an angle of elevation 30°. Mark
40.   A ball thrown by one player reaches            the correct statement
      the other in 2 sec. the maximum                (a) Kinetic energy will be zero at the
                                                             highest point of the trajectory
PHYSICS-I                                     PROJECTILE MOTION       ENTRY -TEST 2023
                Answers Explanations                                                             1
                                                                       5 = (25 sin  )  2 −        10  (2)2
                                                                                                 2
                          v cos 
                            2   2                                                   g             g
                     h=                                                For                                                 angle (45  +  ) ,
                            2g
                                                                          u 2 sin(90  + 2 ) u 2 cos 2
4.    (d)                                                              R=                    =
                                                                                   g               g
5.    (b) RTan = 4H max                                                                                                   u 2 sin 2
                                                                 17.   (b) Range is given by                      R=
      (c) H = u sin   H  u 2 . If initial velocity
               2   2
6.                                                                                                                              g
                       2g                                                                          g
                                                                       On moon              gm =       . Hence            Rm = 6 R
      be doubled then maximum height                                                               6
      reached by the projectile will                             18.   (c) For greatest height  = 90°
      quadrupled.                                                              u 2 sin 2 (90 ) u 2
                                                                       H max =                 =    = h (given)
7.    (d)                                                                               2g             2g
                                                                                  u sin 2(45 ) u 2
                                                                                    2   2
8.    (a) An external force by gravity is                              R max =                 =    = 2h
                                                                                       g         g
      present throughout the motion so
                                                                 19.   (c)        R = 4 H cot  , if        R         =         4H             then
      momentum will not be conserved.
                                                                       cot  = 1   = 45 
                   2
                        2
9.    (a) Range = u sin
                     g
                           ; when  = 90  , R = 0               20.   (b)   E ' = E cos 2  = E cos 2 (45 ) =
                                                                                                                      E
                                                                                                                      2
      i.e. the body will fall at the point of                    21.   (b)
      projection after completing one                            22.   (b)
      dimensional motion under gravity.                          23.   (d) Acceleration through out the
10.   (c) R = 4 H cot  .                                              projectile motion remains constant
      When R = H then cot  = 1/4   = tan −1 (4)                     and equal to g.
11.   (c) Because there is no accelerating or                    24.   (c)
      retarding force available in horizontal                    25.   (c)     Time    of   flight = 2 u sin =
      motion.                                                                                                                              g
                                                                       2  50  sin 30
12.   (a) Direction of velocity is always                                              = 5s
                                                                             10
      tangent to the path so at the top of
                                                                 26.   (b) Change in momentum =                                  2mu sin 
      trajectory, it is in horizontal direction
                                                                           = 2  0.5  98  sin 30 = 45 N-s
      and acceleration due to gravity is
      always in vertically downward                              27.   (d) R = 4 H cot  , if R= 3 H then                            cot  =
                                                                                                                                               3
                                                                                                                                                   
                                                                                                                                               4
      direction. It means angle between v                              = 538 '
            
      and g are perpendicular to each other.                     28.   (c) Became vertical downward
13.   (d)      R = 4 H cot  if    = 45       then                   displacement of both (barrel and
      R = 4 H cot(45 ) = 4 H                                          bullet) will be equal.
                                                                                                    sin 2 1 sin 2 30 
                                                                                              
                                                                                     2    2
                      u 2 sin(2  15 ) u 2
14.   (b)   R15  =                    =    = 1 .5 km            29.   (b) As H = u sin         H1
                                                                                                   =         =           =
                              g          2g                                            2g                        H22
                                                                                                                           sin  2      sin 60
                u sin(2  45 ) u
                 2                  2                                  1/4
                                                                           =
                                                                             1
      R45  =                  =   = 1 . 5  2 = 3 km
                      g          g                                     3/4 3
                                                                                    v 2 sin 2
15.   (a)       For         vertical      upward        motion   30.   (d)   R=                    = 12 sin −1  gR2 
              1                                                                          g                            v 
      h = ut − gt 2
              2
PHYSICS-I                                                                   PROJECTILE MOTION                        ENTRY -TEST 2023
                     2u sin                                                          46.   (c) Since horizontal component of
31.   (a)    T=               = 10 sec  u sin  = 50 m/s
                        g
                                                                                            velocity is constant, hence momentum
                          sin 2  (u sin  )2 50  50
      H = u
                     2
                                 =           =        = 125 m                               is constant.
                          2g          2g       2  10
32.   (b) For complementary angles range                                              47.   (b)    H =
                                                                                                       u 2 sin 2 
                                                                                                                   and T = 2u sin  
                                                                                                                      2g                                    g
      will be equal.                                                                                 4 u sin 
                                                                                                         2       2
                                                                                            T2 =
      (b) R = u sing 2 = (500 ) 10
                                   sin 30 
               2                2
33.                                          = 12 .5  10 3 m                                            g2
                                                                                             TH                 T =
                                                                                                    2
                                                                                                             8             8H    2H
                                                                       2u sin                           =                    =2
34.   (a)                                                           T=                                      g              g     g
                                                                          g
             Tg       2  9 .8                                                       48.   (d) R = 4 H cot  , if R = 4                     3H   then    cot  = 3
      u=            =            = 19 . 6 m / s
            2 sin    2  sin 30                                                              = 30 
                         u 2 sin 2                                                                       2      2
                                                                                                                   
35.   (c)    R=                     = R  u 2 . So             if the speed of        49.   (c) Hmax = u sin
                              g                                                                             2g
      projection doubled, the range will                                                    According                                   to               problem
      becomes four times,                                                                    u1 sin 45  u 2 sin 60 
                                                                                                2
                                                                                                        =
                                                                                                         2             2       2
      i.e., 4  50 = 200 m                                                                       2g           2g
                                                                                                             sin 2 60 
                                                                                                     2
                                                                                                u1                       u     3 /2               3
36.   (c) Range will be equal for                                                                       =               1 =       =               .
                                                                                                u2   2
                                                                                                             sin 2 45   u2   1/ 2                2
      complementary angles.
                                                                                      50.   (c)
37.   (a) When the angle of projection is
      very far from 45° then range will be                                            51.   (d)              R = 4 H cot  ,       if    = 45  then R = 4 H      
                                                                                            R 4
      minimum.                                                                               =
                                                                                            H 1
                                                     2
      Maximum height = u2 g = 100
                               2
                                                                   = 50 m
45.   (c)    R m ax =
                            u2
                             g
                               = 100      u = 10              10 = 32 m / s
PHYSICS-I   PROJECTILE MOTION   ENTRY -TEST 2023