Answer:
Explanation:
Work done in lifting the weight once = mgh
= 20 x 9.8 x (1.9+1.7)
= 705.6 J
= 705.6 / 4.2 calorie
= 168 cals
Total energy to be spent = 600 x 10³ cals
No of times weight is required to be lifted
= 600 x 10³ / 168
= 3.57 x 10³ times
Total time to be taken = 2 x 3.57 x 10³
= 7.14 x 10³ s
=119 minutes .
I am walking to the end of the room holding three textbooks.
Playing tug of war
Moving boxes to move out of your house
Answer:
hypernova making a black hole, and merger of two neutron stars
Gravitational force = G ( m1 m2 ) / r²
3 = G ( m1 m2 ) / ( 10 )²x = G ( m1 m2 ) / ( 5 )²We shall divide those two equations:3 / x = 1/100 / 1/25 = 25 / 100 = 1 / 4x · 1 = 3 · 4x = 12Answer:C. 12 N
Voltage = (current) x (resistance)
= (19 A) x (14 ohms) = 266 volts .
Note: Be careful using that thing !
It's dissipating
I² R = (19 A)² x (14 ohms) = 5,054 watts ! ! !
That's an awful lot of power for a blow-dryer !
The dryer is certainly not using very much of that power to run the fan.
Most of it is being used to heat air. 5 kilowatts is more power than most
toasters or microwave ovens use, so please be careful with how much of
your hair or skin you expose to that hot-air blast. You could probably cook
a meatloaf with it.