Board Competitive Exams 41 Two projectiles of same mass and with same velocity are thrown at an angle 60 and 30 with the horizontal then which will remain same 1 Time of flight 2 Range of projectile 3 Maximum height acquired 4 All of these 42 Two particles having mass M and m are moving in a circular path having radius R and r If their time periods are same then the ratio of their angular velocities will be 3 1 43 If A B A 181 and B will be 1 90 3 0 R 4 then angle between A 2 120 4 60 44 A particle moves along a circle of radius with constant tangential acceleration If the velocity of the particle is 80 m s at the end of the second revolution after motion has begun the tangential acceleration is 1 40 m s 2 640 m s 4 40 m s 3 160 m s 45 The vector sum of two forces is perpendicular to their vector differences In that case the forces 1 Are equal to each other 2 Are equal to each other in magnitude 3 Are not equal to each other in magnitude 4 Cannot be predicted 46 A wheel has angular acceleration of 3 0 rad s and an initial angular speed of 2 00 rad s In a time of 2 s it has rotated through an angle in radian of 1 10 2 12 3 4 m 47 A particle is moving such that its position coordinates x y are 2 m 3 m at time t 0 6 m 7 m at time t 2 s and 13 m 14 m at time t 5 s 1 2 SECTION D Assertion Reason Type Questions In the following questions a statement of assertion A is followed by a statement of reason R 3 Motion in a Plane 225 Average velocity vector V from t 0 to f 5 s is 1 13 147 3 2 1 1 5 1 If both Assertion Reason are true and the reason is the correct explanation of the assertion then mark 1 2 If both Assertion Reason are true but the reason is not the correct explanation of the assertion then mark 2 3 If Assertion is true statement but Reason is false then mark 3 4 If both Assertion and Reason are false statements then mark 4 A If ALB then A BI IA BI R If ALB then A B is perpendicular to A B A The addition of two vectors P and Q is commutative R By triangle law of vector addition we can prove P Q Q P A A vector cannot be divided by other vector R A vector can be divided by a scalar 4 A At the highest point the velocity of projectile is zero R At maximum height projectile comes to rest A Horizontal range of a projectile is always same for angle of projection with horizontal or 0 with vertical R Horizontal range depends only on angle of projection