4. if the force of friction on a sliding object is 25 n, what amount of force is needed to maintain a constant .if it is has constant velocity then the object is

Which is not true about oxygen-17 and oxygen-18?

An object weigh 40n in air ,weigh 20n when submerged in water,and 30n when submerged in a liquid of unknown liquid density.what is the density of unknown of liquid?

Asmall grinding wheel has a moment of inertia of 4.0×10−5 kg⋅m2 . what net torque must be applied to the wheel for its angular acceleration to be 150 rad/s2 ?