Search & Filtering
280 J of electric energy flows into a certain light bulb every second and some energy is transferred into light energy while some ‘waste’ thermal energy is also generated. If 220 J of thermal energy is generated each second, what is the efficiency of this bulb?
A differential wheel and axle has axles 25 cm and 10 cm in diameter. The load is 750 N and the effort required at an efficiency of 42 percent is 70 N. Calculate the wheel and diameter.
A 500 g bar of ice is initially at -25 °C. Calculate the amount of energy required to vapourize 25% of the substance at 100 °C
A ship’s fuel oil (oil density = 800 kg/m3 ) storage tanks contain oil to a depth of 8 m. If the barometer reading is 750 mm Hg. Determine:
i. The gauge pressure on the plate
ii. The load on the plate due to the oil, if the plate is circular with a diameter of 450 mm
iii. The absolute pressure on the plate
Air is to be compressed in a diesel engine cylinder. The initial pressure and temperature are 105 kN/m2 and 15 °C respectively and the final pressure is 7 MPa. In order to ignite the fuel charge injected at the end of compression, the temperature required is 1100 °C. Calculate the ratio of the initial to the final volume for this to be possible.
An aerobatic aircraft is performing circular loops at the speed of sound, covering spectacularly 340 meters every single second in a flight exhibition. All participants have been warned that they keep their acceleration below 8 times that of the gravitational acceleration to avoid getting dizzy. What is the diameter of the smallest loop that these participants can safely do? Here you may use 10 m/s/s as the gravitational acceleration.
Design a 4-bit combinational logic to subtract one bit from the other. Draw the logic diagram using NAND and NOR Gates
An aerobatic aircraft is performing circular loops at the speed of sound, covering spectacularly 340 meters every single second in a flight exhibition. All participants have been warned that they keep their acceleration below 8 times that of the gravitational acceleration to avoid getting dizzy. What is the diameter of the smallest loop that these participants can safely do? Here you may use 10 m/s/s as the gravitational acceleration.
The human eye is most sensitive to green light of wavelength 505 nm. Experiments have found that when people are kept in a dark room until their eyes adapt to the darkness, a single photon of green light will trigger receptor cells in the rods of the retina. (a) What is the frequency of this photon? (b) How much energy (in joules and electron volts) does it deliver to the receptor cells? (c) To appreciate what a small amount of energy this is, calculate how fast a typical bacterium of mass 9.5 x 10-12 g would move if it had that much energy.
I was going through the topic of entropy and i searched about heat death (which means universe will end after getting too cold for humans to live) but mam we have read alot about increasing temperature and global warming ...mam actually the question is will the universe end (according to science) because of heat death despite global warming (and not end because of global warming)...Will global warming end after heat death of universe?
