Physics Past Questions and Answers

A copper cube weighs 0.25 N in air, 0.17N when completely immersed in paraffin oil and 0.15 N when completely immersed in water.The ratio of upthrust in oil to upthrust in water is

A wheel and axle is used to raise a load of 500 N by the application of an effort of 250 N. If the radii of the wheel and the axle are 0.4 cm and 0.1 cm respectively, the efficiency of the machine is

When a brick is taken from the earth's surface to the moon, its mass

When a brick is taken from the earth's surface to the moon, its mass

The resultant of two forces is 50N. If the forces are perpendicular to each other and one of them makes an angle 0f 30<sup style='font-size: smaller;'>o</sup> with the resultant, find its magnitude.