• Rebirth: réincarnation or renaissance
• Revival: reprise
• Rediscovery: redécouverte
Answer: C. -12 newtons
Explanation: Since, the block is in static equilibrium,
the net force on the block is zero i.e. balance forces are acting on the block.
In the horizontal direction,
force applied+force due to friction = 0
20 N + (-20N) = 0
In the vertical direction as well, net force is zero:
Force due to gravity + force exerted by the ground = 0
12 N + force exerted by the ground = 0
⇒force exerted by the ground = 0 -12 N = -12 N
Thus, the correct option is C. -12 N where negative sign means that the direction of the force due to ground is opposite to the force of gravity.
Answer:
Price elasticity of demand = 0.25
Explanation:
The detailed steps and appropriate derivation is as shown in the attached file.
Answer:
People firstly believe that the planets move in a circular orbit until Newton came up with his hypothesis by inventing calculus so that we could understood and calculated planetary orbits and their accuracy.
Explanation:
- Everyone assumed the planets were perfect circles until Newton came up with an idea. Slowly people would make maps of the orbits that added circles on circles, and they could never really explain about the movement of the planet. They simply say that planets move on circles but they lacked the math to explain or prove it. Then Newton came up with an idea of inventing calculus so that we could understood and calculated planetary orbits and their accuracy.
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- Firstly people used their observations and say that the orbits looked like circles, then they developed their models and did the math, and proposed their hypothesizes which were wrong, until Newton came along and tried to match a model that used elliptical orbits and invented the math that allowed him to make predictions with it. His model worked for most planets.
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- However he could not explain about the planet Mercury for instance since it was a very strange orbit. Then after the Einstein's theory of General Relativity he could also explain very deeply about it.
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- Scientists and Astronomers made hypothesizes that there was another planet orbiting too close to the sun to see with telescopes, called Vulcan, that explained mercury's orbit before Einstein's theory. Then long after we had telescopes which was good enough to see if there was a planet orbiting closer to the sun than mercury.
Answer:
The time required by the Athlete to work off 1.00 lb of body fat = 0.296 minute
Explanation:
1 lb of body fat = 4.1 k cal
1 k cal = 4.184 Kilo joule
1 lb of body fat = 4.1 × 4.184 = 17.1544 Kilo joule
Athlete expends 3480 Kilo joule in one hour
⇒ Time required to expand 3480 Kilo joule = 60 minute
⇒ Time required to expand 1 Kilo joule = 
⇒ Time required to expand 17.1544 Kilo joule = × 17.1544 = 0.296 min
Therefore the time required by the Athlete to work off 1.00 lb of body fat = 0.296 minute
