The maximum horizontal range of a projectile is \(400~\text{m}\). The maximum value of height(ever possible) attained by it will be:
1. \(100~\text{m}\)
2. \(200~\text{m}\)
3. \(400~\text{m}\)
4. \(800~\text{m}\)
Figure shows four paths for a kicked football. Ignoring the effects of air on the flight, rank the paths according to initial horizontal velocity component, highest first
(1) 1, 2, 3, 4
(2) 2, 3, 4, 1
(3) 3, 4, 1, 2
(4) 4, 3, 2, 1
A man standing on a road holds his umbrella at 30° with the vertical to keep the rain away. He throws the umbrella and starts running at 10 km/hr. He finds that raindrops are hitting his head vertically, the speed of raindrops with respect to the road will be:
(1) 10 km/hr
(2) 20 km/hr
(3) 30 km/hr
(4) 40 km/hr
A river is flowing from east to west at a speed of \(5\) m/min. A man on south bank of river, capable of swimming \(10\) m/min in still water, wants to swim across the river in shortest time. He should swim:
1. | Due north |
2. | Due north-east |
3. | Due north-east with double the speed of the river |
4. | None of the above |
A thief is running away on a straight road in a jeep moving with a speed of 9 m/s. A police man chases him on a motor cycle moving at a speed of 10 m/s. If the instantaneous separation of jeep from the motor cycle is 100 m, how long will it take for the policemen to catch the thief
(1) 1 second
(2) 19 second
(3) 90 second
(4) 100 second
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 downwards. To another man standing on ground the rain will appear:
1. | To fall vertically downwards |
2. | To fall at an angle going from west to east |
3. | To fall at an angle going from east to west |
4. | The information given is insufficient to decide the direction of the 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 is
(1) 2h
(2) 2h 40 min
(3) 1h 20 min
(4) Cannot be estimated with the information given
A 120 m long train is moving towards west with a speed of 10 m/s. A bird flying towards east with a speed of 5 m/s crosses the train. The time taken by the bird to cross the train will be
(1) 16 sec
(2) 12 sec
(3) 10 sec
(4) 8 sec
A boat crosses a river with a velocity of 8 km/h. If the resulting velocity of boat is 10 km/h, then the velocity of river water is
(1) 4 km/h
(2) 6 km/h
(3) 8 km/h
(4) 10 km/h
A vector \(\vec{a}\) is turned without a change in its length through a small angle \(d\theta\)
1. \(0,\)
2. \(ad\theta,\) \(0\)
3. \(0,\) \(0\)
4. none of these