What layer of the atmosphere is made mostly of hydrogen and helium?

You place a block of wood on its smallest face on a table. When you turn the block onto its largest face, what changes? OA. Force increases. OB. Temperature decreases. OC. Density increases. OD. Pressure decreases.

What two pieces of information do h need to describe force?

Which of these statements best describes an effect of changes in Earth's magnetic field? Southern lights are seen at high altitude places like Alaska. Northern lights are seen at low latitude places like Michigan.

At noon, ship a is 130 km west of ship b. ship a is sailing east at 25 km/h and ship b is sailing north at 15 km/h. how fast is the distance between the ships changing at 4:00 pm

Defination of centre of curvature of a lens.

Which of the following elements is the most reactive? Beryllium Calcium Magnesium Barium

A flash of white light containing all the colors of the visible spectrum in air shines straight down on the surface of a pool.

A car accelerates uniformly from 0 to 15m/s in 5 s. Calculate acceleration.

Which device would a sleep researcher use to monitor a sleeping person's brain waves?

An experiment is performed to obtain the value of a physical property. If the true (i. e., correct) value of the property is 50 and the measured (i. e., experimental) value is 32, the percent error of the experimental result is: