Someone pls help I don’t understand this

Answer:

a)   F = 3.3 10⁴ N,  b)  F = 2.2 10³ N,  c) force when rigid is 15 times greater than when bending the knees

Explanation:

For this exercise we can use the relationship between work and the variation of kinetic energy

          K₀ = ½ m v²

the final kinetic energy is zero because the person is stationary

          W = (∑ F) x

          W = W x - F w

the weight is in the same direction of the displacement therefore the work is positive and the force applied, by the floor, is in the opposite direction to the displacement, consequently the work is negative

we substitute

          ( W-  F ) x = 0-K₀

           F = W + K₀ /x  

          F = mg + [tex]\frac{1}{2} \frac{mv^2 }{2x}[/tex]  

          F = m ( g+  [tex]\frac{v^2 }{2x }[/tex]  )

Let's use kinematics to find the velocity of the person when reaching the floor

           v² = v₀² - 2g (y + y₀)

the initial velocity is true and when reaching the ground y = 0

          v² = -2 g (0-yo)

we calculate

          v = [tex]\sqrt{2 ] 9.8 \ 0.800}[/tex]

          v = - 3.96  m/s

the direction of this velocity is vertical down

let's calculate

a) x = 1.50 cm = 0.0150 m

           F = 62.0 (3.96² / 2 0.0150 + 9.8)

           F = 3.3 10⁴ N

b) x = 30 cm = 0.30 m

           F = 62.0 (3.96² / 2 0.30 + 9.8)

           F = 2.2 10³ N

c) to compare the force let's look for the relationship between the two

           [tex]\frac{F_{rigid} }{ F_{flexible} }[/tex] = 3.3 10⁴ / 2.2 10³

           \frac{F_{rigid}  }{ F_{flexible} } = 15

therefore see that the force when rigid is 15 times greater than when bending the knees

Answer:

It is D

Explanation:

The explanation why the marble undergoes oscillatory motion should be option D.

An object should be classified as the motion oscillates related to an equilibrium position because of the restoring force or torque.  This motion should be significant to study various phenomena like electromagnetic waves, molecules. etc. In the case when the gravitational force should be exerted on the marble here the magnitude and the direction should be the same.

learn more about the motion here: https://brainly.com/question/16335988

Answer:

The total initial volume of air in the tire is 800 cm³

Explanation:

Given;

volume of air in the bicycle pump, V₁ = 200 cm³

volume of the tire, V₂ = 800 cm³

The total initial volume of air in the tire is 800 cm³ and when the pump is pushed in, the total volume of air in the tire becomes 200 cm³. This occurs because the new air pumped into the tire through the bicycle pump compresses the air that was previously in the tire and raises the pressure of the tire that was initially flat.

From Boyle's law, a decrease in volume causes an increase in pressure.

Answer:

sugar free

Explanation:

she should most likely take anything sugar free and avoid any bread, bread can increase your blood level as well, my mother had pre diabetes and what she did was eat salads and drink vegetable smoothies until your sugar goes down. splitting an entrée won't do anything, you technically get the same amount of sugar so at the point just eat the whole meal.

Answer:

[tex]F_o=437Hz[/tex]

Explanation:

From the question we are told that:

Frequency of Turning fork [tex]F_t=440Hz[/tex]

Number of beats detected [tex]n=3[/tex]  

Generally the equation for Original frequency [tex]F_o[/tex] of the string  is mathematically given by

[tex]F_o=F_t-F_b[/tex]

Where

[tex]F_b[/tex] Beat frequency

[tex]F_b=1Hz*n\\F_b=1Hz*3[/tex]

Therefore

[tex]F_o=440-3[/tex]

[tex]F_o=437Hz[/tex]

Answer:

D. Pacific plate

Explanation:

took the quiz

Answer:

strength

Explanation:

Answer:

Potential energy

Explanation:

Since the boy is holding is, it is not moving. So, it has potential energy. Also, since it is in the air, it has gravitational potential energy.

Answer:

[tex]0.059\ \text{m/s}[/tex]

Explanation:

[tex]m_1[/tex] = Mass of bullet = 4.2 g

[tex]u_1[/tex] = Initial velocity of bullet = 0

[tex]m_2[/tex] = Mass of hunter with rifle = 69.5 kg

[tex]u_2[/tex] = Initial velocity of hunter with rifle

[tex]v_1[/tex] = Final velocity of the bullet = 970 m/s

[tex]v_2[/tex] = Final velocity of the hunter with the rifle

As the momentum of the system is conserved we have

[tex]m_1u_1+m_2u_2=m_1v_1+m_2v_2\\\Rightarrow v_2=\dfrac{m_1u_1+m_2u_2-m_1v_1}{m_2}\\\Rightarrow v_2=\dfrac{0-0-0.0042\times 970}{69.5}\\\Rightarrow v_2=-0.059\ \text{m/s}[/tex]

The recoil speed of the hunter is [tex]0.059\ \text{m/s}[/tex] in the opposite direction of the bullet.

Answer:

Gravitational force is the force of attraction on a body by earth. Example - Leaves and fruits fall from a tree downwards towards the ground due to the gravitational pull. ... T-shirt for is basically the force Of attraction On a body And this force of attraction on the body is by Earth.

Intermolecular forces act between molecules. ... Intermolecular forces are weaker than intramolecular forces. Examples of intermolecular forces include the London dispersion force, dipole-dipole interaction, ion-dipole interaction, and van der Waals forces.

Explanation:

Explanation:

I am sure you are Clear. Thanks.

Answer:

Explanation:

a)

To pass the Coulomb barriers and undergo nuclear fusion, alpha particles must be burned at high temperatures. As a result, the ignition temperature needed for this reaction is 5.4168 × 10¹⁰ K. Helium must be burned at a high temperature and density. As a result, this must occur for hot stars with high densities.

b)

The amount of energy given up can be calculated as follows:

[tex]_2He^4 + _2He^4 \to _4Be^8 ---- (1) \\ \\ _4Be^8 + 2_He^4 \to _6C^{12} ---(2)[/tex]

where;

[tex]M(_2He^4) = 4.002603 \ u \\ \\ M(_4Be^8) = 8.005305 10 \ u[/tex]

Therefore, from the reaction (1);

[tex]Q = \Big ( M(_2He^4) + M(_2He^4) - M(_4Be^8) \Big ) ( 931.5 \ MeV) \\ \\ = \Big ( 2(4.002603 \ u) - (8.00530510 \ u) \Big) \Big ( 931.5 \ MeV/u \Big) \ \\ \mathbf{= -0.092 \ MeV}[/tex]

From the second reaction:

[tex]Q = \Big ( M(_4Be^8) + M(_2He^4) - M(_6C^{12}) \Big ) ( 931.5 \ MeV) \\ \\ = \Big ( 8.00530510 \ u +4.002603 \ u -12 \ u \Big) \Big ( 931.5 \ MeV/u \Big) \ \\ \mathbf{= 7.37 \ MeV}[/tex]

Answer: a

Explanation:

when a car dives on a road it a makes friction but it need something to push it or start it which is the balloon in this example

(sorry if im wrong)

Answer:

Static force of friction = 428.75 N

Kinetic Force of Friction = 281.75 N

Explanation:

The static force of friction is equal to Coefficient of static Friction * Mass * g

= 0.35 *125 * 9.8

= 428.75 N

The Kinetic force of friction is equal to Coefficient of kinetic Friction * Mass * g

= 0.23 *125 * 9.8

= 281.75 N

Answer:

dfdfsdf s

Explanation:

fsdfsd fsd fds f vsdvads

Answer:

0.5

Explanation:

In this picture,

Answer:

The zygote

Explanation:

The sperm is what fertilized the egg and the zygote is basically part of the female egg cell.

Answer:

the answer is the ovum on edge

Explanation:

Answer:

50N

Explanation:

force it is falling with can be found by mass into acceleration and then devide by half to find force that could stop it in 2 sec

Answer:

He had a cogenital condition

Explanation:

cogenital conditions are present before or at the time of birth and are considered birth defects

Answer:

The answer is C- He had a congential condition.

Explanation:

Edge

Answer:

=> Black holes are points in space that are so dense they create deep gravity sinks. Beyond a certain region, not even light can escape the powerful tug of a black hole's gravity.

=> Anything that ventures too close—be it star, planet, or spacecraft—will be stretched and compressed like putty in a theoretical process aptly known as spaghettification.

[tex] \infty \infty [/tex]

Answer:

hydrogen and helium

Explanation:

i got it 100 percent. Hope this Helps!

Answer:

72mph/sec

Explanation:

The car goes from 100mph to 316mph in three seconds. Meaning it increases its speed by (316 - 100)mph in three seconds. That is 216 mph increase in three seconds. So, we divide the speed increase by the amount of time the increase occurred over. We get:

216mph / 3sec = 72mph/sec, our final answer

Hope it made sense. I would appreciate Brainliest, but no worries.

Answer:Her likelihood of conceiving will be reduced by at least 50%.

Explanation:

EDGE 2020

Answer:

Her likelihood of conceiving will be reduced by at least 50%

Explanation:

took the test on edge, got it right

Answer:

the angle the ladder makes with the floor as seen by an observer on Earth is 71.9°

Explanation:

Given the data in the question and as illustrated in the diagram below.

speed of the ship v = 0.90c

base of the ladder from the wall x₀ = 3.0 m

top of the later above the floor y = 4.0 m

we determine angle θ.

from the diagram,

tanθ = y/x₀

tanθ = y / x₀√( 1 - v²/c² )

we substitute

tanθ = 4.0 / 3.0√( 1 - ((0.9c)²/c²) )

tanθ = 4.0 / 3.0√( 1 - ((0.9²)c²/c²) )

tanθ = 4.0 / 3.0√( 1 - (0.9²) )

tanθ = 4.0 / 3.0√( 1 - 0.81 )

tanθ = 4.0 / 3.0√0.19

tanθ = 4.0 / 1.30766968

tanθ = 3.058876

θ = tan⁻¹( 3.058876 )

θ = 71.8965 ≈ 71.9°

Therefore, the angle the ladder makes with the floor as seen by an observer on Earth is 71.9°

Answer:

speed =distance/time taken

5 m/s

Answer:

[tex]\mathbf{\alpha = 25.88 \ rad/s^2 }[/tex]

Explanation:

Consider the force due to friction:

[tex]F = \mu_kN -------- (1)[/tex]

where;

N = normal reaction

[tex]\mu_k[/tex] = coefficient of kinetic friction.

Via the horizontal direction, the forces of equilibrium are:

[tex]\sum F_x = \sum(F_x) _{eff} \\ \\ N- F_{AB} \ cos \theta = 0 \\ \\ F_{AB} \ cos \theta = N ------ (2)[/tex]

where;

[tex]\theta[/tex] = angle of AB is associated with the horizontal;

[tex]F_{AB}[/tex] = force exerted by AB

Let's take a look at the equilibrium of forces along the vertical direction.

[tex]\sum F_y = \sum (F_y)_{eff} \\ \\ F+F_{AB} sin \theta - W = 0\\ \\ \mu_k N + F_{AB} sin \theta -mg =0 \\ \\ F_{AB} sin \theta = mg - \mu_kN-------(3)[/tex]

By dividing (3) by (2), we get:

[tex]\dfrac{F_{AB} sin \theta }{F_{AB} cos \theta} = \dfrac{mg - \mu_k N}{N} \\ \\ tan \theta = \dfrac{mg-\mu_kN}{N} \\ \\ Ntan \theta = mg - \mu_kN \\ \\ N(tan \theta + \mu_k ) = mg \\ \\ N = \dfrac{mg}{tan \theta + \mu_k}[/tex]

By replacing the obtained value of N into:

[tex]F = \mu_k N[/tex]

we have:

[tex]F = \mu_k (\dfrac{mg}{tan \theta + \mu_k}) \\ \\ \\ F = \dfrac{mg \mu_k}{tan \theta + \mu_k}[/tex]

Moment about center A can be expressed as:

[tex]\sum M_A = \sum (M_A) _{eff} \\ \\ Fr = I \alpha\\ \\ \alpha = \dfrac{Fr}{I}[/tex]

where;

[tex]\alpha[/tex] = angular acceleration of the disc

I = mass moment of inertia

r = radius of disc

By replacing F and I; ∝ becomes:

[tex]\alpha = \dfrac{\bigg( \dfrac{mg \mu_k}{tan \theta + \mu_k} \bigg) r}{\dfrac{1}{2}mr^2}[/tex]

[tex]\alpha = \dfrac{2g}{r} \dfrac{\mu_k}{tan \ \theta + \mu_k}------- (4)[/tex]

where;

g = 9.8 m/s²

r = 0.18 m

[tex]\mu_k = 0.54[/tex]

θ = 60°

[tex]\alpha = \dfrac{2(9.8)}{0.18} (\dfrac{0.54}{tan \ 60+ 0.54})[/tex]

[tex]\mathbf{\alpha = 25.88 \ rad/s^2 }[/tex]

The coefficient of static friction be in order to keep the quarter from sliding outward when the turntable is in motion will be 0.31.

It is a type of opposition force acting on the surface of the body that tries to oppose the motion of the body. its unit is Newton (N).

Mathematically it is defined as the product of the coefficient of friction and normal reaction.

On resolving the given force and acceleration in the different components and balancing the equation gets. The friction force balances centripetal force.

The given data in the problem will be;

m is the mass =6.25 g

r is the radius =25 cm=0.25 m

t is the time = 0.18 sec

μ is the coefficient of static friction =?

[tex]\rm F_c= mw^2r \\\\ f= \mu mg \\\\ F_C=f\\\\ mw^2r= \mu mg \\\\ \rm \mu = \frac{\omega^2r}{g} \\\\ \rm \mu = (\frac{2\pi}{1.8} )^2\frac{0.25}{9.81} \\\\ \rm \mu = 0.31[/tex]

Hence the coefficient of static friction will be 0.31.

To know more about friction force refer to the link;

https://brainly.com/question/1714663

Answer:

Because the coefficient of restitution is less than 1.

This coefficient is 1 for a perfectly elastic collision.

Some of the energy of the fall is absorbed by the ball so the ball cannot return to its original height.

Also, you have the effects of air resistance and some energy absorption of the the reflecting surface.

Explanation:

because a tertiary prevention is when the person is already infected with the disease