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3 years ago

What statement is true about a spring?

2 answers:

8 0

I think B is the most correct, because logically it's harder to bend a stiffer spring than it is to bend a softer one. Also, I don't think length comes into play. So B.

brilliants [131]3 years ago

4 0

Answer:

B. The stiffer the spring, the greater the force required to restore its position.

Explanation:

The 'restoring force' (the force required to restore the position of a spring) is given by:

$F=-kx$

where

F is the restoring force

k is the spring constant, which determines its stiffness (the higher the value of k, the stiffer the spring)

x is the displacement of the spring relative to its natural length

From the formula, we see that the higher the value of k (so, the stiffer the spring), the larger the restoring force, so the correct option is

B. The stiffer the spring, the greater the force required to restore its position

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PLEASE HELP ASAPPPP!!!!!

Minchanka [31]

She was actually removing energy

6 0

3 years ago

A worker pushes horizontally on a 35.0 kg crate with a force of magnitude 112 N. The coefficient of static friction between the

OLga [1]

Answer: a) -127 N b) No. c) -112 N d) 40 N e) 15 N

Explanation:

a) Friction force always oppose to the relative movement between two surfaces, and, provided that be less than the fs max, adopt any value to counteract the applied force.

The fs max, is the horizontal component of the contact force, and can be written as follows:

Fs max = us . Fn

As the block is at rest in the vertical direction, this means that Fn must be numerically equal to the weight of the object:

Fn = m g = 35 kg. 9.8 m/s2 = 343 N → Fs max = 0.37. 343 N = 127 N

b) Now, as the applied force is smaller than Fs max, this means that the friction force, is equal and opposite to the applied forcé, i.e., -112 N, so the crate doesn´t move.

c) Please see above.

d) As explained above, the maximum friction force, is proportional to the normal force, which adopts any value needed to satisfy the Newton´s 2nd Law.

So, if we diminish the normal force, we can lower the máximum friction force, helping to the worker to move the crate.

The mínimum needed normal force, will be the one that satisfies the following:

Fs max = F applied = us Fn = 112 N = 0.37. Fn.

Solving for Fn, we get Fn= 303 N

So, the difference between the original normal force and the new one, will be the mínimum upward force needed to make the crate to move, as follows:

Fup = 343 N -303 N = 40 N

e) If we keep the normal force unchanged, but add an horizontal force to help the worker, we will need that the sum of both forces, will be equal to the Fs max, as follows:

Fh + Fapp = 127 N → Fh = 127 N – 112 N = 15 N

5 0

3 years ago

Atom X contains seven protons and seven neutrons. atom Z contains seven protons and eight neutrons. which of the following state

stiks02 [169]

Answer:

The correct answer is option A: they are isotopes.

Explanation:

From atom X we know that the number of protons is 7 and the number of neutrons is 7 and from atom Z we know that the number of protons is 7 and the number of neutrons is 8.

Since the number of protons of atom X and atom Z is the same, we have that atom X and atom Z is the same element. The difference in the number of neutrons tells us that atom X and atom Z are isotopes. Remember that an isotope is one element that has atoms with different numbers of neutrons.

The mass number is given by:

$A = p + n$

Where <em>n</em> is the number of neutrons and <em>p </em>is the number of protons.

For atom X and atom Z we have:

$A_{x} = 7 + 7 = 14$

$A_{z} = 7 + 8 = 15$

Hence, they have a different mass number.

We know that the element with 7 protons is nitrogen. The first isotope is $^{14}_{7}N$ and the second isotope is $^{15}_{7}N$ . Both isotopes are stables (they are not radioactive).

Therefore, the correct answer is option A: they are isotopes.

I hope it helps you!

3 0

3 years ago

A small block is released from rest from the edge of a large hemispherical frictionless bowl with radius 3 m. As the mass passes

andreyandreev [35.5K]

Explanation:

It is given that,

Radius of bowl, r = 3 m

A small block is released from rest from the edge of a large hemispherical friction less bowl. Let v is the speed of the mass when it passes through the bottom of the bowl and u is the initial speed of the mass, u = 0. Using conservation of energy as :

$mgh=\dfrac{1}{2}mv^2$

h = r = 3 m

$v=\sqrt{2gh}$

$v=\sqrt{2\times 9.8\ m/s^2\times 3\ m}$

v = 7.66 m/s

v = 7.7 m/s

So, the speed of the mass at the bottom of the bowl is 7.7 m/s. Hence, this is the required solution.

4 0

3 years ago

Where do you find cations on the periodic table

saw5 [17]

Answer:

Explanation:

The electronic configuration of many ions is that if a closes noble gas to them in a periodic table.

An Anion is a ion that has gained one or more electron, acquiring a negative charge.

A Cation is a ion that has lost one or more electron, gaining a positive charge.

5 0

3 years ago