A sample of a material has 200 radioactive particles in it today. Your great-grandmother measured 400 radioactive particles in it 100 years ago. 100 years from today, how many radioactive particles will the sample have?

Crystal of a chemical in a lab slowly disappear from their container they do not become liquid this is an example of which change of state

Tory has a mass of 40kg. She sleds down a hill that has a slope of 25 degrees. what is the component of her weight that is along her direction of motion?

A 20kg cannonball is fired into a stationary 500kg boulder at on the edge of a 125m high cliff. If the cannonball remains in the boulder and together they land 140m horizontally from the edge of the cliff, what was the initial speed of the boulder?

Which causes seismic waves? A. convection in the mantle B. movements of the plates C. movements of the core D. gravity in the mantle

A helium nucleus contains two protons and two neutrons. The mass of the helium nucleus is greater than the combined masses of two protons and two neutrons because binding energy has been added. True False

A fishbowl has a circular opening with a diameter of 13 cm. The fishbowl sits upright on a table in a magnetic field of 0.00110 T that is directed downward. What is the flux through the glass of the bowl? -1.5*10^-5 Wb -4.5*10^-4 Wb 0.0 Wb -5.

Why do cars need a cooling system in conjunction with the engine

A runner starts from rest and has an acceleration of 3 m/s2. How fast is she running after 1.1 seconds

Which best blocks X-ray particles and can therefore be observed more closely through the use of this technology?

A light ray travels inside a horizontal plate of glass, striking its upper surface at an angle of incidence of 50°. This ray is totally internally reflected at the glass-air boundary. A liquid is then poured on top of the glass.