A simple pendulum is suspended in a lift which 5. is going up with an acceleration 5 m/s^2. An electric field of magnitude 5 N/C and directed vertically upward is also present in the lift. The charge of the bob is 1 mC and mass is 1 mg. Taking g =  and length of the simple pendulum 1m, the time period of the simple pendulum is

Anonymous User Physics 20 Apr, 2019 1 Answer 345 views




X-ray diffraction studies show that copper crystallises in an fcc unit cell with cell edge of 3.608×10-8 cm. In a separate experiment, copper is determined to have a density of 8.92 g/cm3, calculate the atomic mass of copper

Rajkumar Yadav Chemistry 19 Apr, 2019 1 Answer 163 views






A number consists of three digits which are in G.P. the sum of the right hand and left hand digits exceeds twice the middle digit by 1 and the sum of the left hand and middle digits is two third of the sum of the middle and right hand digits. Find the numbers?

Anonymous User Maths 18 Apr, 2019 1 Answer 950 views















A sounding body emitting a frequency of 150 Hz is dropped from a height. During its fall under gravity it crosses a balloon moving upwards with a constant velocity of 2m/s one second after it started to fall. The difference in the frequency observed by the man in balloon just before and just after crossing the body will be:

Given that -velocity of sound = 300m/s; g = 10m/s2.

(A) 4

(B) 6

(C) 8

(D) 12

Kirti Gulati Physics 16 Apr, 2019 1 Answer 66 views




A passenger is standing d distance away from a bus. The bus begins to move with constant acceleration a. To catch the bus, the passenger runs at a constant speed u towards the bus. What must be the minimum speed of the passenger so that he may catch the bus?

Anonymous User Physics 15 Apr, 2019 1 Answer 245 views

A driver takes 0.30 s to apply the brakes after he sees a need for it. This is called the reaction time of the driver. If he is driving a car at a speed of 54 km/h and the brakes cause a deceleration of 5.0m/s2, find the distance travelled by the car after he sees the need to put the brakes on ?

Anonymous User Physics 15 Apr, 2019 1 Answer 83 views



The force of repulsion between two point charges is F, when these are at a distance of 1 m. Now the point charges are replaced by spheres of radii 25 cm having the charge same as that of point charges. The distance between their centres is 1 m, then compare the force of repulsion in two cases.

Anonymous User Physics 13 Apr, 2019 1 Answer 1302 views









A particle is moving along a straight line along x-axis with an initial velocity of 2 m/s towards positive x-axis. A constant acceleration of 0.5 m/s2 towards negative x-axis starts acting on particle at t=0. Find velocity (in m/s) of particle at t = 2s.

Rahul Kumar Physics 12 Apr, 2019 1 Answer 72 views

A body is thrown up with a speed 49 m/s. It travels 5 m in the last second of its upward journey. If the same body is thrown up with a velocity 98 m/s, how much distance (in m) will it travel in the last second. (g = 10 m/s2)?

Rahul Kumar Physics 12 Apr, 2019 1 Answer 170 views