Sound waves travel faster in : group of answer choices

cool air

vacuum

air at - 40°c

warm air

icy cold air

According to the law of conservation of mass, in a chemical reaction the total starting mass of all the reactants equal the total final mass of all the products. true or 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?

Awoman holds a book by placing it between her hands such that she presses at right angles to the front and back covers. the book has a mass of m = 1.8 kg and the coefficient of static friction between her hand and the book is μs = 0.67. no attempt 50% part (a) what is the weight of the book, fgb in newtons?