Escape Speed

Q. Two identical balls each of mass 4 kg are moving towards each otherwith speed of 2m/s and 3m/s respectively.They undergo perfectly elastic collision. The impulse impartedby one ball on otheris

Q. 102. If angle of projection is 30 then how many times the horizontal range is to maximum height

Q. Two satellites of earth S1 and S2 are moving in the same orbit. The mass of S1 is four times S2. Which one of the following statements is true? (1.) The potential energies of earth and satellite in the two cases are equal (2.) S1 and S2are moving with the same speed (3.) The kinetic energies of the two satellites are equal (4.) The time period of S1 is four times that of S2

Q. an object is released at one bank into a river flowing with speed 5 km/h towards east.Air is blowing with speed 5 km/h towards north .ifwidth of river is 200 m then minimum time taken by floating object to reach the other bank i

Q. The US athlete Florence Griffith-Joyner won the 100 m sprint gold medal at Seol Olympic 1968 setting a new Olympic record of 10.54s.Assume that she achieved her maximum speed in a very short-time and then ran the race with that speed till she crossed the line.Take her mass to be 50 kg.Calculate the kinetic energy of Griffith-Joyber at her full speed.Assuming that the track, the wind, etc.offered an average resistance of the tenth of her weight, calculate the workdone by the resistance during the run.What power Griffith-Joyner had to exert to maintain uniform speed?

Q. a stone is thrown with a speed of 10m/s at an angle of projection 60 degree.find its height above the point of projection when it is at a horizontal dis†an ce 3m from the thrower?

Q. Does the escape speed of a body from the earth depend on (a) the mass of the body, (b) the location from where it is projected, (c) the direction of projection, (d) the height of the location from where the body is launched?

Q. What will be the escape speed from a planethaving volume 27 times that of earth and the samemean density as that of the earth? (Take escapespeed from the earth 11.2 km/s, earth and planetare perfectly sphere)

Q. A particle is projected with horizontal surface with 2/7 m/sec at an angle 60 with horizontal Angular speed of the particle is at the highest point with respect to point of projection is

Q. A particle is projected vertically upwards from the surface of the earth (radius $R)$ with a speed equal to one-fourth of escape velocity. The maximum height attained by it from the surface of the earth is

1. $\frac{R}{5}$
2. $\frac{R}{10}$
3. $\frac{R}{15}$
4. $\frac{R}{20}$

Q.

An unmanned space probe is to be thrown with such a velocity that it does not return back to Earth. It should be thrown with:

1. velocity > (2GM)^1/2/ R necessarily

2. a great velocity but nothing more can be said

3. velocity = (2GM)^1/2/R

4. velocity ≥ (2GM/R)^1/2

Q. 50. If y=x -1/2x2 is the equation of trajectory , then the time of flight will be - a) 2/under root g b) 3/ under root g c) 4/ under root g d) 2root2 / under root g

Q.

If $v_e$ and $v_o$ represent the escape velocity and orbital velocity of a satellite corresponding to a circular orbit of radius R, then

1. $v_e=v_o$

2. $\sqrt{2}{v}_o=v_e$

3. $v_e=\frac{v_o}{\sqrt{2}}$

4. $v_e$ and $v_o$ are not related

Q. 3. When a particle is projected at some angle to the horizontal, it has a range R and time of flight t1. If the same particle is projected with the same speed at some other angle to have the same range, its time of flight is t2, then 1) t1 + t2 = 2R/g 2) t1 - t2 = R/g 3) t1t2 =2R/g 4) t1t2 = R/g

Q. if particle is executing SHM with time period T then the time period of its total mechanical energy is

Q.

An engine generates a power of 10 kW. In how much time will it raise a mass of 200 kg through a height of 40m.

1. 8 sec

2. 4 sec

3. 5 sec

4. 10 sec

Q. 48.A fighter plane is flying horizontally at an altitude of 1.5km with speed 720 km/hr. At what angle of sight w.r.t. horizontal when the target is seen, should the pilot drop the bomb in order to attack the target?

Q. 46. If the time of flight of a bullet over a horizontal range R is T, then angle of projection with horizontal is

Q. A shell of mass $M$ and radius $R$ has a point mass $m$ placed at a distance $r$ from its centre. The gravitational potential energy $U\left(r\right)$ vs $r$ will be

1. 
2. 
3. 
4. 

Q. A boat moves perpendicular to the bank witha velocity of 7.2 km/h. The current carries it150 m downstream, find the velocity of thecurrent. (The width of the river is 0.5 km)

Q. Power Dilivered to an object of mass M is P. Velocity of object at time T is V .If it will start from rest then Calaulate power dilivered ty engine in time t

Q. if the time of flight of a bullet over a horizontal range R is T then the angle of projection with the horizontal is

Q. 68.The horizontal range of projectile is maximum for which angle of projection

Q. an object is released at bank of river flowng with speed 5 km per hour towards east .air is blowing with speed 5 km per hour toward north if width of river is 200 m .then time taken by floating object to reach the other bank .

Q. A rocket is launched normal to the surface of the Earth , away from the sun, along the line joining the sun and the Earth. The Sun is 3×10^5 times heavier than the earth and is at a dis†an ce 2.5×10^{4 }times larger than the radius of the Earth.The escape velocity from Earths gravitational field is V_e =11.2 km s^{-1}. The minimum initial velocity(V_s) required for the rocket to be able to leave the Sun-Earth system is closest to (Ignore the rotation and revolution of the earth and the presence of any other planet.)

Q. 49.A 1000kg rocket is fired from the surface of earth so that its exhaust speed is 1000m/s relative to the rocket. If initial acceleration of the rocket is 5m/s2 then mass of fuel burning per second is (a) 15kg/s (b) 5kg/s (c) 10kg/s (d) 20kg/s

Q. if the earth were to suddenly contract to 1/n of its present radius without any change in its mass the duration of new day will be

Q. Consider the statements for an oblique collision of two sphere having different masses and initial velocities;

Statement 1: Initial and final velocity of both the spheres perpendicular to line of impact will remain same.
Statement 2: Impulse due to collision of the spheres will not affect initial velocity of sphere along the line of impact.

1. Statement 1 is true but statement 2 is false.
2. Statement 2 is true but statement 1 is false.
3. Both statements are true.
4. Both statements are false.

Q. The escape speed of a projectile on the earth's surface is $11.2km{s}^{-1}$. A body is projected out with thrice this speed. What is the speed of the body far away from the earth? Ignore the presence of the sun and other planets.

Q.

The ratio of the K.E. required to be given to the satellite to escape earth's gravitational field to the K.E. required to be given so that the satellite moves in a circular orbit just above earth atmosphere is

1. One

2. Two

3. Half

4. Infinity