A man weighing 80 kg is standing in a trolley weighing 320 kg. The trolley is resting on frictionless horizontal rails. If the man starts walking on the trolley with a speed of 1 m/s, then after 4 sec his displacement relative to the ground will be
1. 5 m
2. 4.8 m
3. 3.2 m
4. 3.0 m
Two men \(P\) & \(Q\) are standing at corners \(A\) & \(B\) of square \(ABCD\) of side \(8\) m. They start moving along the track with constant speed \(2\) m/s and \(10\) m/s respectively. The time when they will meet for the first time, is equal to:
1. \(2\) sec
2. \(3\) sec
3. \(1\) sec
4. \(6\) sec
A boat is sent across a river in perpendicular direction with a velocity of 8 km/hr. If the resultant velocity of boat is 10 km/hr, then velocity of the river is :
(1) 10 km/hr
(2) 8 km/hr
(3) 6 km/hr
(4) 4 km/hr
A boat is moving with velocity of in river and water is moving with a velocity of with respect to ground. Relative velocity of boat with respect to water is:
(1)
(2)
(3)
(4)
A boat moves with a speed of 5 km/h relative to water in a river flowing with a speed of 3 km/h and having a width of 1 km. The minimum time taken around a round trip(returning to the initial point) is:
(1) 5 min
(2) 60 min
(3) 20 min
(4) 30 min