CBSE
The dimensions of gravitational constant are
A ball is thrown from height 'h' and another from '2h'. The ratio of time taken by the two balls to reach ground is
2:1
1:2
Dimension of relative density is
kgm-3
ML-3
dimensionless
M2L-6
Near earth's surface, time period of a satelliteis 4 hrs. Find its time period at height '4R' from the centre of earth
32 hrs
8hrs
16hrs
Radius of orbit of satellite of earth is R. Its kinetic energy is proportional to
R
The ratio of electrostatic and gravitational forces acting between electron and proton separated by a distance 5×1011m will be (charge on electron =1.6×10-19 C, mass of electron =9.1×10-31 kg, mass of proton =1.6×10-27 kg, G=6.7×10-11 Nm2/kg2 )
2.36×1039
2.36×1040
2.36×1041
2.34×1042
Two planets are revolving around the earth with velocities v1 and v2 and in radii r1 and r2 ( r1 > r2 ) respectively. Then :
v1 = v2
v1 > v2
v1 < v2
The earth of mass =6×1024 kg revolves around the sun with an angular velocity of 2×10-7 rad/s in a circular orbit of radius 1.5×108 km. The force exerted by the sun on earth is
6×1019 N
18×1025 N
36×1021 N
27×1039 N
Acceleration due to gravity at earth's surface is 'g'ms-2 . Find the effective value of gravity at a height of 32 km from sea level (Re=6400km)
0.5 gms-2
0.99 gms-2
1.01 gms-2
0.90 gms-2
A ball is thrown upwards, it takes 4sec to reach back to the ground. Find its initial velocity
30ms-1
10ms-1
40ms-1
20ms-1