How much physical activity do children and trens need?

A. 50 minutes at least twice a week

B. 50 minutes at least five days a week

C. 150 minutes a week

D 150 minutes at least five days a week

Why was the second law of motion invented?

According to the law of conservation of energy what ultimatly happens to the total amount of energy in the universe?

Most tornadoes carry wind speeds that range from A. 267 to 322 km per hour. B. 1 to 105 km per hour. C. 178 to 266 km per hour. D. 105 to 177 km per hour.

What is meant by the following statement? "Inertia is directly proportional to mass." Inertia and mass are the same thing. Inertia and mass are the same size. Inertia increases as mass decreases. Inertia increases as mass increases.

A particular frost-free refrigerator uses about 710kWh of electrical energy per year. Express this amount of energy in J, kJ, & Cal.

Suppose you read in the newspaper that a new planet has been found. Its average speed in its orbit is 33 kilometers per second (km/s). When it is closest to its star, it moves at 31 km/s, and when it is farthest from its star, it moves at 35 km/s.

What happens when light from a flashlight strikes Water droplets from a mist of water

What is the length of a box in which the minimum energy of an electron is 1.5*10^-18 J?

Describe how to calibrate a candy thermometer

A water drops falls from the roof of a house during 3s, how high is the house?