Answer:
D. the linear velocity of the point of contact (relative to the inclined surface) is zero
Explanation:
The force of friction emerges only when there is relative velocity between two objects . In case of perfect rolling , there is no sliding so relative velocity between the surface and the point of contact is zero . In other words the velocity of point of contact becomes zero , even though , the whole body is in linear motion . It happens due point of contact having two velocities which are equal and opposite . One of the velocity is in forward direction and the other velocity which is due to rotation is in backward direction . So net velocity of point of contact becomes zero . Due to absence of sliding , displacement due to friction becomes zero . Hence work done by friction becomes zero.
<span>anwser will be
F = ma
where
F = force exerted on the bullet
m = mass of the bullet = 5 gm (given) = 0.005 kg.
a = acceleration of the bullet
Substituting appropriately,
F = 0.005a --- call this Equation 1
Next working equation is
Vf^2 - Vo^2 = 2as
where
Vf = velocity of the bullet as it leaves the muzzle = 326 m/sec (given)
Vo = initial velocity of bullet = 0
a = acceleration of bullet
s = length of the rifle's barrel
Substituting appropriately,
326^2 - 0 = 2(a)(0.83)
a = 64,022 m/sec^2
the anwser will be
Substituting this into Equation 1,
F = 0.005(64,022)
F =320.11 Newtons
Hope this helps. </span><span>
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Hydrogen has one proton whereas helium has two protons in its nucleus.
<h3>How hydrogen and helium atoms different from one another?</h3>
Atoms of hydrogen have a single proton in their nucleus and a single electron in the lowest energy level while on the other hand, Helium atoms have two protons in the nucleus and two electrons in the lowest energy level. In this way, we can say that the atomic number of hydrogen is 1 whereas the atomic number of helium is 2 because of the presence of two protons. Hydrogen atom has no neutron while on the other hand, the helium atom has one neutron in its nucleus.
So we can conclude that Hydrogen has one proton whereas helium has two protons in its nucleus.
Learn more about atom here: brainly.com/question/6258301
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Momentum is a vector quantity. The direction of the momentum vector is the same as the direction of the velocity of the ball. In a previous unit, it was said that the direction of the velocity vector is the same as the direction that an object is moving.
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