Page 1 :
DEPARTMENT OF PHYSICS, , Physics, Time : 1.00 hr xi Marks : 20, , , , , , , , Description Of Motion In One Dimension, , 1) Ariver is flowing from W to E with a speed of 5 m/min. A man can swim in still water with a, velocity 10 m/min. In which direction should the man swim so as to take the shortest possible, path to go to the south., , A) 30° with downstream B) 60° with downstream, , C) 120° with downstream D) southSouth, , 2) Atrain is moving towards east and a car is along north, both with same speed. The observed, direction of car to the passenger in the train is, , A) East-north direction B) West—north direction, , C) South-east direction D) None of these, , 3) An express train is moving with a velocity v,. Its driver finds another train is moving on the, same track in the same direction with velocity v2. To escape collision, driver applies a, retardation a on the train. the minimum time of escaping collision will be, , 22, , MI v, , 4 B)t, = 12 C) None D) Both, , 4) Two bodies of different masses m, and m), are dropped from two different heights a and b., The ratio of the time taken by the two to cover these distances are, , Ajt=, , Aja:b B)b:a C) fa: vb D) a®: b?, , 5) A body is released from a great height and falls freely towards the earth. Another body is, released from the same height exactly one second later. The separation between the two, bodies, two seconds after the release of the second body is, , A) 4.9m B) 9.8m C) 19.6 m D) 24.5m, , 6) A body is released from the top of a tower of height h. It takes t sec to reach the ground., Where will be the ball after time t/2 sec, , A) At h/2 from the ground B) At h/4 from the ground, , C) Depends upon mass and volume of the D) At 3h/4 from the ground, body, , 7) Aparticle is projected up with an initial velocity of 80ft/sec . The ball will be at a height of 96 ft, from the ground after, , A) 2.0 and 3.0 sec B) Only at 3.0 sec C) Only at 2.0 sec D) After 1 and 2 sec
Page 2 :
8) Astone thrown upward with a speed u from the top of the tower reaches the ground with a, velocity 3u. The height of the tower is, , A) 3u?/g B) 4u2/g C) 6u?/g D) 9u?/g, , 9) A balloon is at a height of 81 m and is ascending upwards with a velocity of 12 m/s. A body of, 2kg weight is dropped from it. If y = 10 m/s”, the body will reach the surface of the earth in, , A)1.5s B) 4.025 s C)5.4s D)6.75s, , 10) A body starts to fall freely under gravity. The distances covered by it in first, second and third, second are in ratio, , A)1:3:5 B)1:2:3 C)1:4:9 D)1:5:6, , 11) With what velocity a ball be projected vertically so that the distance covered by it in 5‘", second Is twice the distance It covers in its 6'" second (g = 10 m/s”), , A) 58.8 m’s B) 49 mis C) 65 m’s D) 19.6 mis, , 12) A stone Is thrown with an initial speed of 4.9 m/s from a bridge in vertically upward direction., It falls down in water after 2 sec. The height of the bridge is, , A) 4.9m B) 9.8m C) 19.6 m D) 24.7m, , 13) A stone is shot straight upward with a speed of 20 m/sec from a tower 200 m high. The speed, with which it strikes the ground Is approximately, , A) 60 m/sec B) 65 m/sec C) 70 m/sec D) 75 m/sec, , 14) A body freely falling from the rest has a velocity “v" after it falls through a height "h". The, distance it has to fall down for its velocity to become double, is, , A)2h B)4h c)6h D) 8h, , 15) The time taken by a block of wood (initially at rest) to slide down a smooth inclined plane 9.8, m long (angle of inclination is 30°) is, , a“, , , , Lit, ns, , A) 5 sec B) 2 sec C) 4 sec D) 1 sec, , 16) A body projected vertically upwards with a velocity u returns to the starting point in 4, seconds. If y = 10m/sec®, the value of uis, , A) 5 m/sec B) 10 m/sec C) 15 m/sec D) 20 m/sec
Page 3 :
17) Time taken by an object falling from rest to cover the height of h, and h is respectively t; and, tg then the ratio of t; to to is, , A)hy : he B) Vy: he C)hy : 2he D) 2h, : hy, , 18) A body thrown vertically upwards with an initial velocity u reaches maximum height in 6, seconds. The ratio of the distances travelled by the body in the first second and the seventh, second is, , Aj1:1 By) 11:1 c)1:2 D)1:11, , 19) Another body with double the mass thrown up, with double initial velocity will reach a, maximum height of, , A) 200 m B) 16m c) 80m D) 40m, , 20) A body Is thrown vertically upwards with a velocity u . Find the true statement from the, following, , A) Both velocity and acceleration are zero at its highest point, B) Velocity is maximum and acceleration is zero at the highest point, C) Velocity is maximum and acceleration is g downwards at its highest point, , D) Velocity is zero at the highest point and maximum height reached is u*/2g