(16.8 kW) means (16,800 joules/second)
Energy in 1 hour = (1 hour) x (16,800 J/s) x (3,600 s/hour)
Energy = (16,800 x 3,600) J
Energy = 60,480,000 Joules
Energy = 60.48 MJ
Answer:
The correct option is;
D) The force exerted on the astronaut by Earth is equal to the force exerted on Earth by the astronaut
Explanation:
According to Newton's third law of motion, in nature, for every action, there is an equal and opposite reaction, such that if a first object exerts a certain amount of force on a second object, the second object will exert a force of equal magnitude and opposite direction to that exerted by the first object
Therefore, the gravitational force exerted by Earth on the astronaut, is equal to the force exerted by the astronaut on Earth.
This thermal energy flows as heat within the box and floor, ultimately raising the temperature of both of these objects.
Answer:
Energy lost due to friction is 22 J
Explanation:
Mass of the ball m = 4 kg
Initially velocity of ball v = 6 m/sec
So kinetic energy of the ball ![KE=\frac{1}{2}mv^2](https://tex.z-dn.net/?f=KE%3D%5Cfrac%7B1%7D%7B2%7Dmv%5E2)
![KE=\frac{1}{2}\times 4\times 6^2=72J](https://tex.z-dn.net/?f=KE%3D%5Cfrac%7B1%7D%7B2%7D%5Ctimes%204%5Ctimes%206%5E2%3D72J)
Now due to friction velocity decreases to 5 m/sec
Kinetic energy become
![KE=\frac{1}{2}\times 4\times 5^2=50J](https://tex.z-dn.net/?f=KE%3D%5Cfrac%7B1%7D%7B2%7D%5Ctimes%204%5Ctimes%205%5E2%3D50J)
Therefore energy lost due to friction = 72 -50 = 22 J
Answer: 10 m/s
Explanation: Velocity/Time
50/5= 10
:)