Rain is falling vertically with a speed of 35 ms−135 ms−1. Winds starts blowing after sometime with a speed of 12 ms−1 in east to west direction. At what angle should a boy waiting at a bus stop hold his umbrella?
1. | 16∘ with the vertical |
2. | 15∘ with the vertical |
3. | 19∘ with the vertical |
4. | 19∘ with the horizontal |
A motorboat is racing towards the north at 25 km/h and the water current in that region is 10 km/h in the direction of 60∘ east of the south. The resultant velocity of the boat is:
1. | 12 km/h at 23.4∘ east of west |
2. | 22 km/h at 23.4∘ north of east |
3. | 22 km/h at 23.4∘ east of north |
4. | 20 km/h at 23.4∘ north of west |
A particle starts from the origin at t=0 with a velocity of 5.0ˆi m/s and moves in the x-y plane under the action of a force that produces a constant acceleration of (3.0ˆi+2.0ˆj) m/s2. What is the speed of the particle at the instant its x-coordinate is 84 m?
1. 36 m/s
2. 26 m/s
3. 1 m/s
4. Zero
Rain is falling vertically with a speed of 35 m/s. A woman rides a bicycle with a speed of 12 m/s in the east-to-west direction. What is the direction in which she should hold her umbrella?
1. | in the vertical direction only. |
2. | 19∘ with vertical towards east. |
3. | 19∘ with vertical towards the west. |
4. | 19∘ with vertical towards the south. |
Galileo, in his book Two new sciences, stated that for elevations that exceed or fall short of 45∘ by equal amounts, the ranges:
1. | are equal to each other. |
2. | are not equal to each other. |
3. | are sometimes equal and sometimes not equal to each other. |
4. | depends on the difference between the angles. |
A hiker stands on the edge of a cliff 490 m above the ground and throws a stone horizontally with an initial speed of 15 m/s. Neglecting air resistance, the time taken by the stone to reach the ground and the speed with which it hits the ground are, respectively: (Take g=9.8 m/s2)
1. | 10 s and 99 m/s |
2. | 10 s and 15 m/s |
3. | 5 s and 99 m/s |
4. | 5 s and 15 m/s |
A cricket ball is thrown at a speed of 28 m/s in a direction 30∘ above the horizontal. The time taken by the ball to return to the same level is:
1. 2.5 s
2. 2.9 s
3. 3.5 s
4. 3 s
An insect trapped in a circular groove of radius 12 cm moves along the groove steadily and completes 7 revolutions in 100 s. What is the angular speed of the motion?
1. | 0.62 rad/s | 2. | 0.06 rad/s |
3. | 4.40 rad/s | 4. | 0.44 rad/s |
An insect trapped in a circular groove of radius 12 cm moves along the groove steadily and completes 7 revolutions in 100 s. Is the acceleration vector a constant vector? What is its magnitude?
1. yes, 2.3 cm/s2
2. no, 5.3 cm/s2
3. yes, 5.3 cm/s2
4. no, 2.3 cm/s2