Gravitational force between two point masses m and M

Suppose a tunnel is made in earth which passes through its centre If an object is dropped from R height from earth surface above the tunnel If its 2 R speed at depth from earth surface in tunnel is 2 NGM 12R mass of earth and R is radius of earth then value of N is Given M is

4 Zero A point mass m is placed at a distance R from the surface of a solid sphere of mass m and radius R The gravitational potential energy of this system of point mass and sphere is 1 2 Gm 28 2 2 Gm R

three parallel straight wires placed perpendicular to plane of paper carrying same current I along the 03 same direction is BO 2 a Hoi 2nd d AO 90 shown in figure Magnitude of force per unit length on the middle wire B is given by NEET 2017 b 2 01 c nd d v oi 0 nd d 2 Hoia 2 nd

5 An apple of mass 0 25 kg falls from a tree What is the acceleration of the apple towards the earth Also calculate the acceleration of the earth towards the apple Mass of the earth 5 983 x 1024 kg Radius of the earth 6 378 106 m and G 6 67 x 10 11 Nm kg 2

BEGINNER S BOX 9 If two forces act in opposite direction then their resultant is 10N and if they act mutually perpendicu their resultant is 50N Find the magnitudes of both the forces

Electric potential in an electric field is given as V K r K being constant if position vector r 21 33 6k then electric field will be 21 31 6k K 343 61 2j 3k K 343 1 3 21 3j 6k K 243 31 2j 6k K 243 2 4

Example 18 In a double slit pattern 6000 the first order and tenth order maxima fall at 12 50 mm and 14 75 mm from a particular reference point If is changed to 5500 A find the position of zero order and tenth order fringes other arrangements remaining the same fris

A planet is moving in an elliptical orbit T U E and L are its kinetic energy potential energy total energy and magnitude of angular momentum respectively then which of the following statement is true 1 T is conserved 2 Vis always positive 3 is always negative OMO L is conserved but the direction of vector L 11

direction An artificial satellite is moving in a circular orbit of radius 42250 km Calculate its speed if it takes 24 hours to revolve around the earth 845

10 The distance between the centres of the earth and the moon is 60 times the radius of the earth Calculate the centripetal acceleration of the moon Acceleration due to gravity on the earth s surface 10 m s Ans 1 360 m s 2 2 1 The mean distance of earth from sun is 1 496 108 km and its sidereal revolution period is 365 3 days The sidereal revolution periods of the planets Venus and Mars are 224 7 days and 687 0 days respectively Estimate the mean distances of these planets from the Ans 1 082 108 km 2 279 x 108 km sun 0