Which statement correctly describes mass-energy equivalence?

In a system, when potential energy decreases, then entropy also decreases. true false

A2000 kg car is rounding a curve of radius 200 m on a level road. the maximum frictional force the road can exert on the tires of the car is 4000 n. what is the highest speed at which the car can round the curve?

Ihave a density of 1.61g/cm^3 and a mass of 28g. find the missing value