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 .
Answer:
1.
Upon analysis of the results, a hypothesis can be rejected or modified, but it can never be proven to be correct 100 percent of the time. For example, relativity has been tested many times, so it is generally accepted as true, but there could be an instance, which has not been encountered, where it is not true.
2.Mass is the amount of matter in a body, normally measured in grams or kilograms etc. Weight is a force that pulls on a mass and is measured in Newtons. So on Earth, Weight would be your (mass x acceleration( 9.8 ) . Density, there are lots of kinds of density I guess, but the one you are talking about is density = mass / volume. Density basically means how much mass is occupied in a specific volume or space. Different materials of the same size may have different masses because of its density. Density in this case is measured in kg / m^3 or kg / L or g / m^3 etc where the numerator is a unit of mass and the denominator a unit of volume.
3.The density of an object determines whether it will float or sink in another substance. An object will float if it is less dense than the liquid it is placed in. An object will sink if it is more dense than the liquid it is placed in.
4. An object will float if the gravitational (downward) force is less than the buoyancy (upward) force. So, in other words, an object will float if it weighs less than the amount of water it displaces. This explains why a rock will sink while a huge boat will float.
5.
Answer:
Fr = 26.83 [N]
Explanation:
To solve this problem we must use the Pythagorean theorem, since the forces are vector quantities, that is, they have magnitude and density. Therefore the Pythagorean theorem is suitable for the solution of this problem.
![F_{r}=\sqrt{(12)^{2}+(24)^{2} } \\F_{r}=26.83[N]](https://tex.z-dn.net/?f=F_%7Br%7D%3D%5Csqrt%7B%2812%29%5E%7B2%7D%2B%2824%29%5E%7B2%7D%20%20%7D%20%5C%5CF_%7Br%7D%3D26.83%5BN%5D)
Answer: Option A
Explanation:
The force of attraction existent between the proton and neutron in the nucleus of an atom is extremely large. When the nucleus splits there is a large release of heat and energy larger than the force present in any of the other options listed.
Answer:
Part a)

Part B)

Explanation:
Part A)
As we know that the point A lies on the top of the loop
so we will have by energy conservation

so the speed at point A is given as




Part B)
Now the force equation at point A is given as

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