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3 years ago

A book is sitting on a desk. What best describes the normal force acting on the book?

Physics

2 answers:

Leni [432]3 years ago

7 0

The upward force the desk pushes on the book

Marat540 [252]3 years ago

4 0

Explanation:

in my opinion I'd say it's gravity because it's making the book stay in it's one and only position pulling the book at the center of the desk

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a student sees a newspaper ad for an apartment that has 1330 square feet of floor space how many square meters are there?

sergey [27]

123.561 square meters

3 0

3 years ago

a steel ball bearing is released from a height hhh and rebounds after hitting a steel plate to a height hhh. what is true about

lbvjy [14]

In collision of the steel ball and the steel plate, the collision is an inelastic collision and there is loss in the kinetic energy.

<h3>What are collisions?</h3>

Collisions occur when two objects that are moving in the same directions or in different direction meet each other and collide.

There are two types of collisions:

elastic collision - the kinetic energy is conserved
inelastic collision - there is a loss in kinetic energy

In the collision of the steel ball and the steel plate, there is loss in the kinetic energy of the steel ball which is converted to sound energy.

In conclusion, the collision of the steel and steel plate is an inelastic collision.

Learn more about collisions at: brainly.com/question/7694106

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4 0

1 year ago

Tennis balls traveling at greater than 100 mph routinely bounce off tennis rackets. At some sufficiently high speed, however, th

Kipish [7]

Answer:

Probability of tunneling is $10^{- 1.17\times 10^{32}}$

Solution:

As per the question:

Velocity of the tennis ball, v = 120 mph = 54 m/s

Mass of the tennis ball, m = 100 g = 0.1 kg

Thickness of the tennis ball, t = 2.0 mm = $2.0\times 10^{- 3}\ m$

Max velocity of the tennis ball, $v_{m} = 200\ mph$ = 89 m/s

Now,

The maximum kinetic energy of the tennis ball is given by:

$KE = \frac{1}{2}mv_{m}^{2} = \frac{1}{2}\times 0.1\times 89^{2} = 396.05\ J$

Kinetic energy of the tennis ball, KE' = $\frac{1}{2}mv^{2} = 0.5\times 0.1\times 54^{2} = 154.8\ m/s$

Now, the distance the ball can penetrate to is given by:

$\eta = \frac{\bar{h}}{\sqrt{2m(KE - KE')}}$

$\bar{h} = \frac{h}{2\pi} = \frac{6.626\times 10^{- 34}}{2\pi} = 1.0545\times 10^{- 34}\ Js$

Thus

$\eta = \frac{1.0545\times 10^{- 34}}{\sqrt{2\times 0.1(396.05 - 154.8)}}$

$\eta = 1.52\times 10^{-35}\ m$

Now,

We can calculate the tunneling probability as:

$P(t) = e^{\frac{- 2t}{\eta}}$

$P(t) = e^{\frac{- 2\times 2.0\times 10^{- 3}}{1.52\times 10^{-35}}} = e^{-2.63\times 10^{32}}$

$P(t) = e^{-2.63\times 10^{32}}$

Taking log on both the sides:

$logP(t) = -2.63\times 10^{32} loge$

$P(t) = 10^{- 1.17\times 10^{32}}$

6 0

3 years ago

Calculate the change in entropy as 0.3071 kg of ice at 273.15 K melts. (The latent heat of fusion of water is 333000 J / kg)

Ostrovityanka [42]

Answer:

374.39 J/K

Explanation:

Entropy: This can be defined as the degree of disorder or randomness of a substance.

The S.I unit of entropy is J/K

ΔS = ΔH/T ..................................... Equation 1

Where ΔS = entropy change, ΔH = Heat change, T = temperature.

ΔH = cm................................... Equation 2

Where,

c = specific latent heat of fusion of water = 333000 J/kg, m = mass of ice = 0.3071 kg.

Substitute into equation 2

ΔH = 333000×0.3071

ΔH = 102264.3 J.

Also, T = 273.15 K

Substitute into equation 1

ΔS = 102264.3/273.15

ΔS = 374.39 J/K

Thus, The change in entropy = 374.39 J/K

3 0

2 years ago

Why does ice melt faster in water than in oil when both liquids are at the same temperature

vekshin1

Water has a high specific heat capacity. Oil has a smaller heat capacity.

7 0

3 years ago

Read 2 more answers