In the figure shown two boats start with different speed

A 300 m c 500 m C a 400 m B 23 Two bikers simultaneously start a race with constant speeds from point A to traverse a triangular track ABC one clockwise and the other in anticlockwise sense They simultaneously cross at B first time after a time interval At 4 min If they continue the race how long after they cross at B first time will they again simultaneously cross at B

1 10 20 10 the position of the other balls in metre height will be 2 15 20 15 3 5 51 20 4 5 10 20 A ball is dropped from a height of 20 m and rebounds with a velocity which is 3 4th of the velocity with which hits the ground What is the time interval between the first and second bounces g 10 m s d sec 2 4 sec 3 5 sec 4 6 sec A particle is thrown upwards from aro

Answer the following questions acceleration 1 Define 2 When is the acceleration of a body negative

24 On a straight section of a highway sensors are installed to measure traffic density For each lane of the highway a sensor runs on an overhead wire On a particular day a sensor running with a speed u 5 km h opposite to the flow of traffic underneath counts N 360 vehicles in a length L 1 km of the highway If all the vehicles are moving with the same constant speed v 40 km h and density of the vehicles is uniform calculate number of vehicles per l 100 m of the lane 05 A trai

A ray of light enters a spherical liquid drop refractive index 3 from air at an angle of incidence 0 0 it suffers two internal reflections not TIR inside the drop and finally comes out of the drop If 0 0 is such that the deviation of the ray with respect to its original direction is minimum find the value of 12 sin 0

A projectile can have the same range R for two angles of projection If t and to be the times of flights in the two cases then the product of the two time of flights is proportional to 1 R 3 1 R 2005 2 1 R 4 R ti 2usin 0 t2 2usin 90 9 2usin 90 9 2 tit 4 usine coset 2R 9 9

P is a point moving with constant speed 10 m s such that its velocity vector always maintains an angle 60 with line OP as shown in figure O is a fixed point in space The initial distance between O and P is 100 m After what time shall P reach O 1 10 sec 2 15 sec 100m 60 v 10m s 3 20 sec 4 20 3 sec

30 An object is dropped from rest Its velocity versus displacement graph is assume downward direction to be positive L 2 1 2 3 4 S S S

A car has to cover the distance 60 km If half of the total time it travels with speed 80 kmh and in rest half time its speed becomes 40 kmh 1 the average speed of car will be a 60 kmh 1 b 80kmh 1 c 120 kmh 1 d 180 kmh

A small ball thrown at an initial velocity u directed at an angle 0 37 above the horizontal collides inelastically e 1 4 with a vertical massive wall moving with a uniform horizontal velocity u 5 towards ball After collision with the wall the ball returns to the point from where it was thrown Neglect friction between ball and wall The time t from beginning of motion of the ball till the moment of its impact with the wall is tan37 3 4 3u 181 A B C 5g 5411 125g D 25g 5411 25g