A cop car's siren has a frequency of 700. Hz. If you are standing on the sidewalk as the cop car approaches you at a speed of 15.0 m/s, what frequency would you hear? The speed of sound is 343 m/s.

The Bohr model of the atom suggest that the protons and neutrons are found in the nucleus and the electrons orbit the nucleus much like planets around the sun.

Where is the center of gravity if the 9.00 kg mass of the barbell itself is taken into account?

When warm water vapor is blown over land in the water cycle what happens?

A 16-Ω resistor is connected in series with another resistor across a 12-V battery. The current in the circuit is 0.42 A. Calculate the value of the unknown resistance.

What is the chemical formula for sodium hydroxide?

Which of these is not a source of the shock waves that lead to protostars?

Which kind of information is known about a person if that person's DNA is in a database? A. how old the person is B. where the person was probably born C. some diseases the person might have D. whether the person is likely to commit a crime

A science teacher ran a marathon. After the race she showed her students the silver blanket she was given to keep her warm. A group of students investigated how the colour of the blanket affected how much infrared radiation is absorbed

Students asked to measure the temperature of a reaction beaker recorded the following temperatures. 103.7°C, 108.4°C, 105.8°C, 104.6°C The actual temperature is 105.1°C. Which measurement is the most precise

Two atoms that are isotopes of one another must have a different number of what? electrons neutrons protons all particles