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2 years ago

A handle or knob is fixed at free end of door.why?

1 answer:

3 0

This is because of something called moments,
moment is the turning Effect of a force.
it is calculated by
moment=force×perpendicular distance from the line of action.
So if there is more distance from pivot the more the moment is for the same force.

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You are helping two friends from our class with a physics problem where a cart is pushed up a ramp. In examining the motion of t

stiks02 [169]

Answer: Acceleration will have 2 components, vertical and horizontal.

Net-vertical component can be positive, zero or negative depending upon the magnitude of the upward component of the applied acceleration.

Net-horizontal acceleration will be equal to the horizontal component of the applied acceleration.

Explanation:

Since acceleration is a vector quantity and the cart is being pushed up the ramp, the ramp would be at some angle to the horizontal and hence there will be vertical and horizontal components of acceleration.

For vertical acceleration:

If the magnitude of the upward component of the applied acceleration is greater than the value of the acceleration due to gravity then the net vertical acceleration will be upward because it will overtake the value of acceleration due to gravity.

In case the upward component of the applied acceleration is lesser than the value of the acceleration due to gravity then the net vertical acceleration will be downward.

For horizontal acceleration:

This component remains unaffected and is equal to the horizontal component of the applied acceleration because there is no other acceleration acting in the horizontal direction.

But the net acceleration will not be solely in the vertical or horizontal direction because the block has to move forward on the inclined ramp so there will always exist a horizontal and a vertical component making the net acceleration to parallel to the ramp in upward direction if the body is going up the ramp.

8 0

2 years ago

Read 2 more answers

A small solid sphere and a small thin hoop are rolling along a horizontal surface with the same translational speed when they en

torisob [31]

This situation has a basis such that the solid sphere and the hoop has the same mass. The analysis could be made backwards . The ball will decelerate fastest, so not roll as high. The sphere will accelerate faster, but this also means it decelerates faster on the way up. Hence the answer is the hoop if the masses are equal

3 0

2 years ago

What is the energy in joules of a mole of photons associated with visible light of wavelength 486 nm?

ivann1987 [24]

Answer:

$2.46\cdot 10^5 J$

Explanation:

The energy of a single photon is given by:

$E=\frac{hc}{\lambda}$

where

h is the Planck constant

c is the speed of light

$\lambda$ is the wavelength

For the photon in this problem,

$\lambda=486 nm=4.86\cdot 10^{-7}m$

So, its energy is

$E_1=\frac{(6.63\cdot 10^{-34} Js)(3\cdot 10^8 m/s)}{4.86\cdot 10^{-7}m}=4.09\cdot 10^{-19} J$

One mole of photons contains a number of photons equal to Avogadro number:

$N_A = 6.022\cdot 10^{23}$

So, the total energy of one mole of photons is

$E=N_A E_1 = (6.022\cdot 10^{23})(4.09\cdot 10^{-19} J)=2.46\cdot 10^5 J$

7 0

3 years ago

Select ALL that apply. The stages of a human's lifespan include:

Alex787 [66]

Answer:

The answers are A and C

Explanation:

the order of a humans lifespan is: Infancy, early childhood, adolescence, adulthood, then elderly

6 0

2 years ago

Read 2 more answers

Choose the sources of gamma rays. Check all that apply.

harina [27]

Answer:

a. Stars all warm objects

c. Some unstable atomic nuclei

Explanation:

Gamma rays are photons of very high energy (beyond 100keV) enough to remove an electron from its orbit.

They have a very short wavelength, less than 5 meters from the peak, and can be produced by nuclear decay, especially in the breasts of massive stars at the end of life.

They were discovered by the French chemist Paul Villard (1860 to 1934).

While X-rays are produced by electronic transitions in general caused by the collision of an electron with an atom at high speed, gamma rays are produced by nuclear transitions.

Gamma rays produce damage similar to those caused by X-rays or ultraviolet rays (burns, cancer and genetic mutations).

The sources of gamma rays that we observe in the universe come from massive stars (hypernovas) or some warm objects on the space that end their lives by a gravitational collapse that leads to the formation of a neutron star or a black hole, as well as unstable radioactive nuclei that emit radiation gamma to reach its steady state.

7 0

3 years ago