Based on the chemical equation, use the drop-down menu to choose the coefficients that will balance the chemical equation:

() Na2HPO4 → () Na4P2O7 + () H2O

The law of reflection of light holds true for a. all mirrors c. plane mirrors and concave mirrors e. only concave mirrors b. only plane mirrors d. plane mirrors and convex mirrors

Which statement describes a scientific theory? A theory states how something behaves without explaining why. A theory is a proven fact that cannot be changed. A theory changes based on new observations and testing.

The phases of the moon are the changing appearances of the moon, as seen from Earth. Which phase happens immediately after a third quarter moon?

Two tuning forks produce sounds of wavelengths of 3.4 meters and 3.3 meters. Given that the speed of sound in air is 340 m/s, approximately what is the beat frequency produced by these two tuning forks?

Between 1911 and 1990, the top of the leaning bell tower at Pisa, Italy, moved toward the south at an average rate of 1.2 mm/y. The tower is 55 m tall. In radians per second, what is the average angular speed of the tower's top about its base?

The intrapleural pressure is - 4 mmHg relative to atmospheric and the transpulmonary pressure is 5 mmHg relative to atmospheric.

A hot-air balloon is 150 feet above the ground when a motorcycle passes directly beneath it (traveling in a straight line on a horizontal road). The motorcycle is traveling at 40 mph.

How do I calculate initial speed by using the slope of a graph? The graph shows the relationship between S { (sin2ϴ) / g} and the average range of a projectile in meters.

You push a 50 kg wooden box across a wooden floor at a constant speed of 1.0 m/s. The coefficient of kinetic friction is 0.15. Now you double the force on the box. How long would it take for the velocity of the crate to double to 2.0 m/s?

A star is in hydrostatic equilibrium when the outward push of pressure due to core burning is exactly in balance with the inward pull of gravity.