How can I disable the government tracking device in my cell phone?
Work done force distance Distance20 m Force mass acc due to gravity 500 10( or more precisely 9.81) 5000 WorK done 500020 100000 Power Work done(energy)/ time 100000/40 2500 W (output) Efficiency (output power)/(input power) i.e input power (output power)/ efficiency 2500/0.8 3125 W
1) Put the cell phone in a plastic bag 2) Wrap it in heavy duty aluminum foil 3) put it inside a thermos or cup full of water
Work done force distance Distance20 m Force mass acc due to gravity 500 10( or more precisely 9.81) 5000 WorK done 500020 100000 Power Work done(energy)/ time 100000/40 2500 W (output) Efficiency (output power)/(input power) i.e input power (output power)/ efficiency 2500/0.8 3125 W
I am pretty sure I'm doing your homework for you, but here goes anywayWork is distance times forceDistance is given as 20mForce is found by multiplying the 500 kg by the gravitational constant 9.81 m/s^2 which gives roughly 4.9 kNTherefore, work equals about 98.1 kNm or kilojoules (kJ)The output power is equal to W/tSince work equals 98.1 kN and time equals 40 seconds, power equals about 2.45 kilowattsIf the efficiency is 0.8, we divide the power by this efficiency to get the input power to the electrical motor: 2.45 kilowatts/.8 3.07 kilowatts For the second question: Assuming the mass is stationary (it has not kinetic energy and negilible thermal energy, etc.), it's energy is all in potential energy, given by PEmgh, where m equals mass, g equal 9.81 m/s^2, and h equals heightHere, PE 50 kg (9.81 m/s^2) 40m 19.62 kJThe power is found similarly to the first problemForce equals 50kg(9.81m/s^2)490.5 N, Work equals 490.5 N40m 19.62 kJ (notice how work is equal to the change in energy in the system, which is not just a coincidence)Power equals 19.62 kJ/20s 980 watts Hope this helps.
I am pretty sure I'm doing your homework for you, but here goes anywayWork is distance times forceDistance is given as 20mForce is found by multiplying the 500 kg by the gravitational constant 9.81 m/s^2 which gives roughly 4.9 kNTherefore, work equals about 98.1 kNm or kilojoules (kJ)The output power is equal to W/tSince work equals 98.1 kN and time equals 40 seconds, power equals about 2.45 kilowattsIf the efficiency is 0.8, we divide the power by this efficiency to get the input power to the electrical motor: 2.45 kilowatts/.8 3.07 kilowatts For the second question: Assuming the mass is stationary (it has not kinetic energy and negilible thermal energy, etc.), it's energy is all in potential energy, given by PEmgh, where m equals mass, g equal 9.81 m/s^2, and h equals heightHere, PE 50 kg (9.81 m/s^2) 40m 19.62 kJThe power is found similarly to the first problemForce equals 50kg(9.81m/s^2)490.5 N, Work equals 490.5 N40m 19.62 kJ (notice how work is equal to the change in energy in the system, which is not just a coincidence)Power equals 19.62 kJ/20s 980 watts Hope this helps.
1) Put the cell phone in a plastic bag 2) Wrap it in heavy duty aluminum foil 3) put it inside a thermos or cup full of water
