General Gravity Problem

Q. A particle is projected vertically upwards from ground with speed 60 m/s. Speed of the particle when it is at height of 55 m is [g = 10 m/s²]

एक कण को धरातल से ऊर्ध्वाधर ऊपर की ओर 60 m/s की चाल से प्रक्षेपित किया जाता है। जब कण 55 m की ऊँचाई पर होता है, तब कण की चाल है [g = 10 m/s²]

1. 50 m/s
2. 40 m/s
3. 55 m/s
4. 35 m/s

Q.

A stone dropped from the top of a building of height $h$. It reaches the ground after $t\text{s}$. From the same building if two stones are thrown (one upwards and other downwards) with the same velocity $u$, and they reach the earth surface after $t_1$ and $t_2$ seconds respectively, then

1. $t=t_1-t_2$

2. $t=\frac{t_1+t_2}{2}$

3. $t=\sqrt{t_1{t}_2}$

4. $t=t_1^2{t}_2^2$

Q.

A ball is thrown up from the top of a tower at 20 m/s velocity. It took the ball 6 sec to fall to the bottom. How high is the tower?

1. 20 m

2. 40 m

3. 30 m

4. 60 m

Q. A ball is dropped on the floor from a height of 10 m. It rebounds to a height of 2.5 m. If the ball is in contact with the floor for 0.01 sec, the average acceleration during contact is

1. $2100m/se{c}^2\left(downwards\right)$
2. $2100m/se{c}^2\left(upwards\right)$
3. $1400m/se{c}^2$
4. $700m/se{c}^2$

Q. The ball goes upto a height of .

1. $\frac{u^2}{2g}$
2. $\frac{u^2}{g}$
3. $\frac{2u^2}{g}$

Q.

As a runaway scientific balloon ascends at 19.6 m/s, one of its instrument packages breaks free of a harness and free-falls. Figure below gives the vertical velocity of the package versus time, from before it breaks free to when it reaches the ground. (a) What maximum height above the break-free point does it rise? (b) How high is the break-free point above the ground?

Take g = 9.8 $m/s^2$

1. $h_{max}$above break free point 19.6 m

   height of break free point 78.4

2. $h_{max}$ above break free point 78.4 m,

   height of break free point 19.6

3. $h_{max}$ above break free point 19.6 m,

   height of break free point 58.8

4. $h_{max}$ above break free point 58.8 m,

   height of break free point 9.8

Q.

A stone is dropped into water from a bridge 44.1 m above the water. Another stone is thrown vertically downward 1 sec later. Both strike the water simultaneously. What was the initial speed of the second stone?

1. 12.25 m/s

2. 14.75 m/s

3. 16.23 m/s

4. 17.15 m/s

Q. A ball is dropped from the top of a tower $120\text{m}$ high and simultaneously another ball is projected vertically upwards from the ground with a speed of $30\text{m/s}$. The two balls will meet after

1. $2\text{s}$
2. $3\text{s}$
3. $4\text{s}$
4. $5\text{s}$

Q. A balloon is rising vertically up with a velocity of 29$m{s}^{-1}$. A stone is dropped from it and it reaches the ground in 10 seconds. The height of the balloon when the stone was dropped from it is$(g=9.8m{s}^{-2})$

1. 100 m
2. 200 m
3. 400 m
4. 150 m

Q.

A stone falls from a balloon that is descending at a uniform rate of 12 m/s. The magnitude of the displacement of the stone from the point of release after 10 sec is

1. 490 m

2. 510 m

3. 610 m

4. 725 m

Q. A ball is dropped from the top of a tower $120\text{m}$ high and simultaneously another ball is projected vertically upwards from the ground with a speed of $30\text{m/s}$. The two balls will meet after

1. $2\text{s}$
2. $3\text{s}$
3. $4\text{s}$
4. $5\text{s}$

Q.
Two balls are thrown, one from a cliff and one from below. How long will they take to collide (t)? What will be the height of collision(h)?

1. t=8 sec, h=80 m
2. t=6 sec, h=80 m
3. t=8 sec, h=0 m
4. t=8 sec, h=40 m

Q. A man drops a ball downside from the roof of a tower of height 400 meters. At the same time another ball is thrown upside with a velocity $50\frac{meter}{sec}$. from the surface of the tower, then they will meet at which height from the surface of the tower

1. 100 meters
2. 320 meters
3. 80 meters
4. 200 meters

Q.
Two balls are thrown, one from a cliff and one from below. How long will they take to collide (t)? What will be the height of collision(h)?

1. t=8 sec, h=80 m
2. t=6 sec, h=80 m
3. t=8 sec, h=0 m
4. t=8 sec, h=40 m

Q. A parachutist after bailing out falls 50 m without friction. When parachute opens, it decelerates at $2\frac{m}{s^2}$. He reaches the ground with a speed of $3\frac{m}{s}$. At what height, did he bail out ?

1. 293 m
2. 111 m
3. 91 m
4. 182 m

Q. The ball will take to come back to the point from where it was thrown.

1. 1 s
2. 8 s
3. 9 s
4. 10 s