Which of the following statements is true? a. a 140-lb. person would weigh more than 140 lbs on the moon because of the increase in gravity. b. earth has a synchronous rotation, when means its rotation and revolution periods are the same length. c. earth's moon is unique because it is larger than any other natural satellite in the solar system. d. leap years add an extra day to february because the earth takes longer than 365 days to orbit the sun.

Ineed the answer to question 1 , i’m desperate

When is a current produced? when the terminals of an electrochemical cell are connected by a wire if the electric circuit is opened in an electrochemical cell if the electrolyte is removed from an electrochemical cell when the electrodes are reversed in an electrochemical cell

1. what is the relationship between wavelength and the penetrating power of an electromagnetic wave? a) the penetrating power has no relationship to the wavelength. b) the penetrating power increases as the wavelength increases. c) the penetrating power decreases as the wavelength increases. d) the penetrating power decreases as the wavelength decreases. 2. as ice melts and turns into water, the speed of sound through the material would most likely do what? justify your answer. a) the speed would not change because the material is always water. b) the speed of sound would increase because the density of water is less than that of ice. c) the speed of sound would increase because energy is added to ice in order to make it melt. d) the speed of sound would decrease because sound travels faster through solids than liquids. 3.which of these waves need a medium to travel through? a) sound b) x-rays c) infrared rays d) visible light