Which is a tool used by scientists to determine the composition of objects?

a hologram

a spectrometer

a wave front

a prism

Explain one effect that burning fossil fuel has on the environment

Ocean currents flow from east to west near the a. Gulf Stream. c. equator. b. poles. d. global winds.

in what distance can a 1500kg automobile be stopped if the brake is applied when the speed is 20m/s and the coefficient of sliding friction is 0.7 between the tyres and the ground?

A taxicab moves five blocks due north, five blocks due east, and another two blocks due north. Assume all blocks are of equal size. What is the magnitude of the taxi's displacement, start to finish?

A commuter train blows its 200-Hz horn as it approaches a crossing. The speed of sound is 335 m/s. An observer waiting at the crossing receives a frequency of 207 Hz. What is the speed of the train?

Visit this website and locate the element mercury, whose chemical symbol is Hg. Click on the square to read about the history, properties, and uses of mercury. Name three uses for mercury.

Ten seconds after starting from rest, a car is moving at 40 m/s. what is the car's acceleration in meters per second per second?

A student builds a simple circuit and a magnet under one of the circuit wires. When the switch is closed charges flow int the circuit and the wire moves

Cite an example in which a force is exerted on an object without doing work on the object

Which equation best expresses the first law of thermodynamics, assuming Q is heat, U is internal energy, and W is work? A.ΔW = ΔQ + ΔU B.ΔW = ΔU - ΔQ C.ΔQ = ΔU+W D.ΔU=Q - W