In 2019, for the first time in history, there were more people over the age of 60 years of age than under 18 years of age.

What ia the energy of an object because of its potential and kinetic energies

A980-kg sports car collides into the rear end of a 2300-kg suv stopped at a red light. the bumpers lock, the brakes are locked, and the two cars skid forward 2.6m before stopping. the police officer, estimating the coefficient of kinetic friction between tires and road to be 0.80, calculates the speed of the sports car at impact. what was that speed?

Aparticle is moving around in a circle and its position is given in polar coordinates as x = rcosθ, and y = rsinθ, where r is the radius of the circle, and θ is in radians. from these equations derive the equation for centripetal acceleration.