Shondra takes notes in class. I. Electromagnetic Waves II. The ability to work - Has many forms - Mechanical III. Potential ener
1 answer:
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Answer:
7572 m/s
Explanation:
The force between two masses separated by a distance r is given as:
Where F is the attractive force between 2 masses, m1 and m2, r is the distance between the centres of the masses and G is the universal gravitation constant, which is
The mass of the earth () is far greater than the mass of the sputnik (
). Therefore
. The mass of the sputnik is neglected, therefore:
But F is actually centripetal acceleration, a = v²/r
Answer:
37357 sec
or 622 min
or 10.4 hrs
Explanation:
GIVEN DATA:
Lifting weight 80 kg
1 cal = 4184 J
from information given in question we have
one lb fat consist of 3500 calories = 3500 x 4184 J
= 14.644 x 10^6 J
Energy burns in 1 lift = m g h
= 80 x 9.8 x 1 = 784 J
lifts required
= 18679
from the question,
1 lift in 2 sec.
so, total time = 18679 x 2 = 37357 sec
or 622 min
or 10.4 hrs
Answer:
The kinetic energy of the phone would increase. The gravitational potential energy of the phone would decrease.
Explanation:
The kinetic energy of an object is proportional to the square of the speed of that object. If air resistance is negligible, the phone would accelerate under gravitational pull and speed up. Hence, the kinetic energy of the phone would increase.
The gravitational field near the surface of the earth is approximately constant. Hence, the gravitational potential energy of the phone would be proportional to its height. As the phone approaches the ground, the height of the phone becomes lower and the gravitational potential energy of the phone would decrease.