Answer:
a) 1450watts
b) 564watts
c) 1.11
Explanation:
Power consumed = IV
I is the current rating
V is the operating voltage
If a blow-dryer and a vacuum cleaner each operate with a voltage of 120 V and the current rating of the blow-dryer is 12 A, while that of the vacuum cleaner is 4.7 A then their individual power rating is calculated thus;
a) For blow-dryer
Operating voltage = 120V
Its current rating = 12A
Power consumed = IV
= 120×12
= 1440watts
b) For vacuum cleaner:
Operating voltage is the same as that of blow dryer = 120V
Its current rating = 4.7A
Power consumed = IV
= 120×4.7
= 564watts
c) Energy used = Power consumed × time taken
Energy used = Power × time
Energy used by blow dryer = 1440×20×60
= 1,728,000Joules
Energy used up by vacuum cleaner = 564×46×60
= 564×2760
= 1,556,640Joules
Ratio of the energy used by the blow-dryer in 20 minutes to the energy used by the vacuum cleaner in 46 minutes will be 1,728,000/1,556,640 = 1.11
Answer:
1.It's the world's most famous equation, but what does it really mean? "Energy equals mass times the speed of light squared." On the most basic level, the equation says that energy and mass (matter) are interchangeable; they are different forms of the same thing.
2.The process releases energy because the total mass of the resulting single nucleus is less than the mass of the two original nuclei.
3.In nuclear reactions, mass is never conserved—some mass is exchanged for energy and energy for mass. Nuclear reactions take place in an atom's nucleus. In a spontaneous nuclear reaction, such as radioactive decay, mass is "lost" and appears as energy in the form of particles or gamma rays.
4.In a nuclear reaction, mass decreases and energy increases. The sum of mass and energy is always conserved in a nuclear reaction.
5.The process releases energy because the total mass of the resulting single nucleus is less than the mass of the two original nuclei.
Explanation:
hope it helps
Answer:
1. 200 metres West
2. Dividing distance by time
3. Speed was unchanged
4. 1800 metres
5. 15 seconds
Explanation:
Running 500 metres West puts you 500 Metres west from the start. Then running 300 metres east puts you 200metres from where you started.
Since displacement is the distance you are from your original position 200 Metres West is the answer
2. Distance = Speed x Time
Rearrange that to get Speed = Distance / Time
3. Acceleration is when the rate of increase or decrease of speed or the direction is changing. When the speed or sirection dont change acceleration is 0
4. Distance = Speed x Time
60 x 30 = 1800 metres
5. Time = Distance / Speed
300 / 20 = 15 seconds
kinetic energy to gravitational potential energy
Answer:
Explanation:
Mass of the cable car, m = 5800 kg
It goes 260 m up a hill, along a slope of 
Therefore vertical elevation of the car = 
Now, when you get into the cable car, it's velocity is zero, that is, initial kinetic energy is zero (since K.E. = 
). Similarly as the car reaches the top, it halts and hence final kinetic energy is zero.
Therefore the only possible change in the cable car system is the change in it's gravitational potential energy.
Hence, total change in energy = mgh = 
where, g = acceleration due to gravity
h = height/vertical elevation
