D Calculate the
average speed of a
car that travels 70 km
in 1.5 hours

Which of the following situations is impossible? a) an object has velocity directed east and acceleration directed east. b) an object has zero velocity but non-zero acceleration. c) an object has constant non-zero velocity and changing acceleration. d) an object has velocity directed east and acceleration directed west. e) an object has constant non-zero acceleration and changing velocity.

Exercise 2. find the wavelength of a photon emitted when an electron jumps from the n = 3 energy level down to the n = 2 energy level. where is this photon in the electromagnetic spectrum?

Which compound is held together by the electrostatic force between two ions? a. co2 b. cci4 c. h2s d. mgf2