Theweight ofof body is 420N .Calculate its mass

AuniformsphericalshellofmassM=4.5kgandradiusR=8.5cmcan rotate about a fixed vertical axis on frictionless bearings. A massless,

Kazeer [188]

Answer:

$v=1.42\frac{m}{s}$

Explanation:

There is no friction in the physical system. Thus, according to the law of conservation of energy, recall that the object is released from rest:

$\Delta E=0\\U=K_R+K_T\\mgh=\frac{I_p\omega_p^2}{2}+\frac{I_s\omega_s^2}{2}+\frac{mv^2}{2}$

Recall that the moment of inertia of a sphere is $I_s=\frac{2MR^2}{3}$ . The angular speed of the pulley is $\omega_p=\frac{v}{r}$ and the angular speed of the sphere is $\omega_s=\frac{v}{R}$ . So, we replace:

$mgh=\frac{I_pv^2}{2r^2}+\frac{2MR^2}{3}\frac{v^2}{2R^2}+\frac{mv^2}{2}\\mgh=v^2(\frac{I_p}{2r^2}+\frac{M}{3}+\frac{m}{2})\\v^2=\frac{mgh}{\frac{I_p}{2r^2}+\frac{M}{3}+\frac{m}{2}}\\\\v=\sqrt{\frac{(0.6kg)(9.8\frac{m}{s^2})(0.82m)}{\frac{3*10^{-3}kg\cdot m^2}{2(0.05m)^2}+\frac{4.5kg}{3}+\frac{0.6kg}{2}}}\\v=1.42\frac{m}{s}$

5 0

3 years ago

Does a resulting force cause acceleration? true or false?

Vesnalui [34]

True...A moving object with a zero resultant force keeps moving at the same speed and in the same direction. If the resultant force acting on an object is not zero, a stationary object begins to accelerate in the same direction as the force. A movingobject speeds up, slows down or changes direction

7 0

4 years ago

The Michelson-Morley experiment a) confirmed that time dilation occurs. b) proved that length contraction occurs. c) verified th

hram777 [196]

Answer:

e) indicated that the speed of light is the same in all inertial reference frames.

Explanation:

In 18th century, many scientists believed that the light just like air and water needs a medium to travel. They called this medium aether. They believed that even the space is not empty and filled with aether.

Michelson and Morley tried to prove the presence and speed of this aether through an interference experiment in 1887. They made an interferometer in which light was emitted at various angles with respect to the supposed aether. Both along the flow and against the flow to see the difference in the speed of light. But they did not find no major difference and thus it became the first proof to disprove the theory of aether.

It thus proved that the speed of light remains same in all inertial frames.

Also, it became a base for the special theory of relativity by Einstein.

5 0

3 years ago

Which statements best describe energy ? check all that apply

Ainat [17]

The statements that describes energy best as follows: 

The total amount of energy in the universe remains constant.
Energy can be converted from one form to another.
Energy cannot be created or destroyed.

Explanation :

The Universe is a closed system of energy from where the thermodynamics first law is quoted i.e. the energy in the closed system remains constant.

The energy in the closed system can neither be created nor destroyed in the absence of external energy supply. However, it keeps on changing from one state to another. These are the absolute statements about the total energy existing in the Universe.

There are many energy forms existing in the Universe such heat, mass, vibrations etc. that consistently change their form from one to another but the total energy amount is always constant until external energy is applied to the system.

According to the quantum theory, even an electron absorbs or emits energy while jumping from one energy band to the other. There is never a case where energy can create or destroy in a closed system.

6 0

4 years ago

In how many ways can the elements of [n] be permuted if 1 must precede 2 and 3 is to precede 4?

sp2606 [1]

No. of ways in the elements of n be permuted is n!/4

Number of elements = n

Number of face in which the element of n be permuted if 1 must proceed 2 and 3 is to precede 4.

n = 4

The possible permutation will

(1,2,3,4), (1,3,2,4),(1,3,4,2),(3,4,1,2),(3,1,2,4),(3,1,4,2)

There are 6 possible outcomes

For n= 5

With 1,2,3,4 we add 5 in the arrangement with above terms

The possible number of permutation

5×6 = 30

When n = 6

30×6 = 180.

So for an element

If 1 precede 2 and 3 is yo precede 4 is

= n! ×6/4!

= n!/4

No. of ways in the elements of n be permuted is n!/4

To know more about permutation:

brainly.com/question/4416319

#SPJ4

4 0

2 years ago

Theweight ofof body is 420N .Calculate its mass​

Theweight ofof body is 420N .Calculate its mass