A cube when moved along one of its faces at a very high speed will look like a
At what speed the mass of the body will be almost doubled
A man sitting in a bus travelling in a direction from west to east with a speed of 40 km/h observes that the rain-drops are falling vertically down. To another man standing on ground the rain will appear ____.
To fall vertically down.
To fall at an angle going from west to east.
To fall at an angle going from east to west.
The information given is insufficient to decide the direction of rain.
A boat takes two hours to travel 8 km and back in still water. If the velocity of water is 4 km/h, the time taken for going upstream 8 km and coming back ____.
2h
2h 40 min
1h 20 min
Cannot be estimated with the information given.
Two trains, each 250 m long, are moving towards each other on parallel lines with velocities of 20 km/hr and 30 km/hr respectively. The time that elapses from the instant when they first meet until they have cleared each other is ____.
20 sec.
36 sec.
30 sec.
None of the above
A train of length 200 m travelling at 30 m/sec. overtakes another of length 300 m travelling at 20 m/sec. The time taken by the first train to pass the second is ____.
30 sec.
50 sec.
10 sec.
40 sec.
Two scooterists P and Q are moving due north at 48 km/hr and 36 km/hr respectively. The velocity of P relative to Q is ____.
12 km/hr due south
12 km/hr due north
84 km/hr due south
84 km/hr due north
A train A is moving towards east with a velocity of 30 km/h and another train B is moving on parallel lines towards west with a speed of 40 km/h. The velocity of train A relative to train B is ____.
10 km/h
70 km/h towards east
70 km/h towards west
None of the above
A car is travelling at a velocity of 10 km/h on a straight road. The driver of the car throws a parcel with a velocity of when the car is passing by a man standing on the side of the road. If the parcel is to reach the man, the direction of throw makes the following angle with the direction of the car ____.
A ship is moving with velocity 12 km/hr in east direction and another ship is moving with velocity 16 km/hr in north direction. The relative velocity of second ship with respect to first ship is ____.
20 km/hr
22 km/hr
18 km/h
A person travelling towards the north-east finds that the wind appears to blow from north, but when he doubles his speed it seems to come from a direction inclined at an angle on the east of north. The true direction of the wind is towards ____.
North-east
North
East
None of the above