A packet is dropped from a balloon which is going upwards with the velocity 12 m/s, the velocity of the packet after 2 seconds will be
1. –12 m/s
2. 12 m/s
3. –7.6 m/s
4. 7.6 m/s
If a freely falling body travels in the last second a distance equal to the distance travelled by it in the first three seconds, the time of the travel is:
1. 66 sec
2. 55 sec
3. 44 sec
4. 33 sec
The effective acceleration of a body, when thrown upwards with acceleration a will be:
1. √a−g2√a−g2
2. √a2+g2√a2+g2
3. (a−g)(a−g)
4. (a+g)(a+g)
A body is thrown vertically upwards with velocity u.u. The distance travelled by it in the fifth and the sixth seconds are equal. The velocity uu is given by (g=9.8 m/s2g=9.8 m/s2)
1. 24.5 m/s24.5 m/s
2. 49.0 m/s49.0 m/s
3. 73.5 m/s73.5 m/s
4. 98.0 m/s98.0 m/s
A parachutist after bailing out falls 50 m50 m without friction. When parachute opens, it decelerates at 2 m/s22 m/s2. He reaches the ground with a speed of 3 m/s3 m/s. At what height, did he bail out ?
1. 293 m293 m
2. 111 m111 m
3. 91 m91 m
4. 182 m182 m
When a ball is thrown up vertically with velocity v0, it reaches a maximum height of 'h'. If one wishes to triple the maximum height then the ball should be thrown with velocity
1. √3vo√3vo
2. 3v0
3. 9v0
4. (3/2)v0
A particle moving in a straight line covers half the distance with a speed of 3 m/s3 m/s. The other half of the distance is covered in two equal time intervals with speeds of 4.5 m/s4.5 m/s and 7.5 m/s7.5 m/s respectively. The average speed of the particle during this motion is:
1. 4.0 m/s4.0 m/s
2. 5.0 m/s5.0 m/s
3. 5.5 m/s5.5 m/s
4. 4.8 m/s4.8 m/s
The acceleration of a particle is increasing linearly with time t as bt. The particle starts from the origin with an initial velocity of v0. The distance travelled by the particle in time t will be:
1. v0t+13bt2v0t+13bt2
2. v0t+13bt3v0t+13bt3
3. v0t+16bt3v0t+16bt3
4. v0t+12bt2v0t+12bt2
A particle starts from rest. Its acceleration (a)(a) versus time (t)(t) is as shown in the figure. The maximum speed of the particle will be:
1. 110 m/s
2. 55 m/s
3. 550 m/s
4. 660 m/s
A car accelerates from rest at a constant rate α for some time, after which it decelerates at a constant rate β and comes to rest. If the total time elapsed is t, then the maximum velocity acquired by the car is
1. (α2+β2αβ) t
2. (α2−β2αβ) t
3. (α+β) tαβ
4. αβ tα+β