Question

Assertion: A machine cannot be 100% efficient in converting energy. Reason: Some energy is always lost to friction and other factors in real-world applications.

Assertion: An object can have kinetic energy can never have zero velocity. Reason: Kinetic energy depends on mass and but not on velocity.

Power is defined as the rate of doing work. A cyclist is moving along a flat road. He has a mass of 70 kg and is pedaling to maintain a constant speed of 5 m/s. The cyclist experiences a frictional force of 20 N acting opposite to the direction of motion.

The potential energy between two atoms in a molecule is given by U(x) = a/x¹² − b/x⁶; where a and b are positive constants and x is the distance between the atoms. The atom is in stable equilibrium when