A firecracker shoots up from a hill 160 feet high with an initial speed of 90 feet per second. Using the formula H (t) = - 16t2 + vt + s, approximately how long will it take the firecracker to hit the ground? ... ?

Neptune is about thirty times farther from the Sun than Earth. How much weaker would the gravitational pull from the Sun on a rock at the orbit of Neptune be compared to at Earth's orbit?

diffraction grating has 5150 lines per centimeter ruled on it. What is the angular separation between the first - and the third-order bright spots on the same side of the central maximum when the grating is illuminated by a beam of light with

Joaquin has hockey practice at the same ice rink where Alton has curling practice. One day, they were both playing on the ice with their equipment.

Which type of mechanical wave needs a source of energy to produce it? a. a transverse wave b. a longitudinal wave c. a surface wave d. all of the above

Compare and contrast fossil fuels and biofuels

The scientific method begins with recognizing a problem. The recognized problem in this scenario is, "Why is the printer in the office not working?" Choose the hypotheses that are testable and from which an experiment can be formed.

The correctly balanced equation for H2O2 → H2O + O2 is

How would an unbalanced chemical equation convey misleading information about what took place during a chemical reaction?

A car rounds a 75-m radius curve at a constant speed of 18 m/s. a ball is suspended by a string from the ceiling the car and moves with the car. the angle between the string and the vertical is:

Emission of light from an atom occurs when an electron