Three point charges are placed at the following points on the x-axis: +2.0×10^-6C at x=0, -3.0×10^-6C at x=40, -5.0×10^-6C at x=120. Find the force (a) on the -3.0×10^-6C charge , (b) on the -5.0×10^-6C charge.​

In a vernier instrument the main scale is in 1/2 mm divisions .vernier is made by redividing 19 such divisions into 20 equal parts. calculate the least count of the instrument.

Africtionless piston-cylinder contains 50 l of saturated liquid r-134a. the piston has a mass and an area resulting in an applied pressure of 500 kpa on the refrigerant. the refrigerant is now heated until its temperature rises to 70∘c. calculate the work (in kj) done during this process.

When solid surfaces slide over each other the kind of friction that occurs is called friction