You see the boy next door trying to push a crate down the sidewalk. He can barely keep it moving, and his feet occasionally slip. You start to wonder how heavy the crate is. You call to ask the boy his mass, and he replies " 48 kgkg ." From your recent physics class you estimate that the static and kinetic coefficients of friction are 0.90 and 0.40 for the boy's shoes, and 0.50 and 0.20 for the crate.

Awind turbine is initially spinning at a constant angular speed. as the wind's strength gradually increases, the turbine experiences a constant angular acceleration 0.173 rad/s2. after making 2870 revolutions, its angular speed is 132 rad/s. (a) what is the initial angular velocity of the turbine? (b) how much time elapses while the turbine is speeding up?

Did the proton move into a region of higher potential or lower potential? did the proton move into a region of higher potential or lower potential? because the proton is a negative charge and it accelerates as it travels, it must be moving from a region of higher potential to a region of lower potential. because the proton is a negative charge and it accelerates as it travels, it must be moving from a region of lower potential to a region of higher potential. because the proton is a positive charge and it slows down as it travels, it must be moving from a region of higher potential to a region of lower potential. because the proton is a positive charge and it slows down as it travels, it must be moving from a region of lower potential to a region of higher potential. request answerpart bwhat was the potential difference that stopped the proton? express your answer with the appropriate units.î”v î” v = nothingnothingrequest answerpart cwhat was the initial kinetic energy of the proton, in electron volts? express your answer in electron volts. ki k i = nothing ev request answerprovide feedback

Afrequency generator sends a 550 hz sound wave through both water and ice. what is the difference in wavelength between the wave produced in ice and the wave produced in water?