You are exploring a newly discovered planet. the radius of the planet is 7.50 × 107 m. you suspend a lead weight from the lower end of a light string that is 4.00 m long and has mass 0.0280 kg. you measure that it takes 0.0645 s for a transverse pulse to travel from the lower end to the upper end of the string. on earth, for the same string and lead weight, it takes 0.0320 s for a transverse pulse to travel the length of the string. the weight of the string is small enough that its effect on the tension in the string can be neglected. assuming that the mass of the planet is distributed with spherical symmetry, what is its mass? express your answer with the appropriate units.

Alinearly polarized electromagnetic wave has an average intensity of 196 w/m^2. this wave is directed towards two ideal polarizers (in real polarizers, transmission is also effected by reflection and absorption). polarizer a is oriented with its transmission axis at an angle of θ_1=20.8∘ with the incident electric field. polarizer b has its axis at an angle of θ_2=63.0∘ with the incident electric field. what is the average intensity of the wave after it passes through polarizer a? what is the average intensity of the wave after it passes through polarizer b? suppose that the two polarizers a and b are interchanged. what would the average intensity be after passing through both polarizers?

Suppose a wire with a current is pushed upward by a magnetic field. how would the wire move if the direction of the current reversed? explain your answer.

For waves in the ocean, the medium of the waves is a. air b. water c. energy d. a passing boat