A farmhand pushes a 23 kg bale of hay 3.9 m across the floor of a barn. If she exerts a horizontal force of 91 N on the hay, how much work has she done?

Answer:

a.49 n

b. 63 n

c. 112 n

Explanation:

a.10 times 9.8 from gravity/2 = 49 n

b. 49n times 4.5/8-4.5 = 63 n

c 49n + 63 n = 112 n

Answer:

(a) The speed is 7.96 m/s

(b) The direction is 76 degree from positive X axis in counter clockwise direction.  

Explanation:

Width of river = 280 m

speed of river, vR = 4.7 m/s towards east

speed of boat with respect to water, v(B,R) = 7.1 m/s at 26 degree west of north

[tex]vR = 4.7 i \\\\v(B,R) = 7.1 (- sin 26 i + cos 26 j) = - 3.1 i + 6.4 j[/tex]

(a) The velocity of boat with respect to ground is

[tex]\overrightarrow{v}_{(B,R)}=\overrightarrow{v}_{(B,G)}-\overrightarrow{v}_{(R,G)}\\\\- 3.1 \widehat{i} +6.4 \widehat{j}=\overrightarrow{v}_{(B,G)} - 4.7 \widehat{i}\\\\\overrightarrow{v}_{(B,G)} = 1.6 \widehat{i} + 6.4 \widehat{j}\\\\{v}_{(B,G)} = \sqrt{1.6^2 + 6.4^2}=6.96 m/s[/tex]

(b) The direction is given  by

[tex]tan\theta = \frac{6.4}{1.6} =4\\\\\theta = 76^o[/tex]

Answer:

The slope of the position time graph gives the velocity.

Explanation:

The slope of the position time graph gives the value of velocity.

In first graph,

The slope is constant in both the parts but positive . So the velocity is also constant and positive for both the parts.  and more than the second part, so the initial velocity is more than the final velocity.

In the second graph,

The slope is constant in both the parts but negative. So, the velocity is constant but negative for both the parts. Initial velocity is more negative than the final velocity.

Answer: its b bro

Explanation:

ajafa'jfbA'FJ

Answer:

[tex]\mathbf{f_o =1.87 \times 10^{11} \ Hz}[/tex]

Explanation:

From the given information:

The elastic potential energy can be calculated by using the formula:

[tex]U_o = \dfrac{1}{2}kR_o^2[/tex]

Making K the subject;

[tex]K = \dfrac{2 U_o}{R_o^2}[/tex]

[tex]k = \dfrac{2\times 1.68 \times 10^{-21}}{(3.82\times 10^{-10})^2}[/tex]

k = 2.3 × 10⁻² N/m

Now; the frequency of the small oscillation can be determined by using the formula:

[tex]f_o = \dfrac{1}{2 \pi}\sqrt{\dfrac{k}{m}}[/tex]

where;

m = mass of each atom = 1.66 × 10⁻²⁶ kg

[tex]f_o = \dfrac{1}{2 \pi}\sqrt{\dfrac{2.3 \times 10^{-2} N/m}{1.66 \times 10^{-26} \ kg}}[/tex]

[tex]\mathbf{f_o =1.87 \times 10^{11} \ Hz}[/tex]

Answer:

130 dB

Explanation:

The equation for decibel level is given by:

[tex]D=10log(\frac{I}{I_n} )\\\\Where\ D\ is\ the \ decibel\ level\ in\ dB, I\ is\ the\ intensity\ in \ W/m^2, \\I_n\ is\ threshold\ intensity\ to\ the\ human\ ear=1*10^{-12}W/m^2\\\\Given\ that\ D=125dB, hence:\\\\125=10log(\frac{I}{1*10^{-12}} )\\\\12.5=log(\frac{I}{1*10^{-12}} )\\\\I=3.2\ W/m^2[/tex]

The intensity for 1 jack hammer is 3.2 W/m², therefore for 3 jack hammers, the intensity = 3 * 3.2 = 9.6 W/m²

[tex]D=10\ log(\frac{I}{I_n} )\\\\D=10*log(\frac{9.6}{1*10^{-12}} )\\\\D=130\ dB[/tex]

Answer:

Explanation:

Given that:

the putty initial speed (u) = 9.10 m/s

distance (s) between hand and the ceiling = 3.50 m

the speed of the putty prior to the time it hits the ceiling can be determined by considering the second equation of motion.

v² - u² = 2as

Since the putty is moving in a vertical motion(i.e. in an upward direction)

v² - u² = -2gs

v² = u² - 2gs

[tex]v = \sqrt{u^2 - 2gs}[/tex]

[tex]v = \sqrt{(9.10)^2 -( 2* 9.8) (3.50 -0)}[/tex]

[tex]v = \sqrt{82.81 -19.6 (3.50)}[/tex]

[tex]v = \sqrt{82.81 -68.6}[/tex]

[tex]v = \sqrt{14.21}[/tex]

v = 3.77 m/s

2.

The time it takes to reach the ceiling from the moment it leaves your hand can be calculated by using the first equation of motion:

v = u + at

In an upward direction

v = u - gt

making time t the subject;

v - u = -gt

[tex]t = \dfrac{v-u}{-g}[/tex]

[tex]t = \dfrac{3.77 - 9.10}{-9.8}[/tex]

[tex]t = \dfrac{-5.33}{-9.8}[/tex]

t = 0.54s

Answer:

D. Hydrogen

Explanation:

The sun is a big ball of gas and plasma. Most of the gas — 91 percent — is hydrogen.

Answer:

D. Hydrogen

Explanation:

Hydrogen makes up most of the Sun. It is nearly 91 percent.

Answer:

0 N

Explanation:

Applying,

F = qvBsin∅................. Equation 1

Where F = Force on the charge, q = charge, v = Velocity, B = magnetic charge, ∅ = angle between the velocity and the magnetic field.

From the question,

Given: q = 4.88×10⁻⁶ C, v = 265 m/s, B = 0.0579 T, ∅ = 0°

Substitute these values into equation 1

F = ( 4.88×10⁻⁶)(265)(0.0579)(sin0)

Since sin0° = 0,

Therefore,

F = 0 N

I am sure it help you with that much ☺️

Explanation:

pleasae give me some thanks please good morning sister

Answer:

25

Explanation:

5 theroical name indvivdual perspective asssssoitive each persp

Answer:

OD. -9.8 m/s2

Explanation:

The only force vertical force that is acting on the skier is gravity and since its pulling him back it's a negative force down the y axis.

Answer:

The number of electrons transferred from one ball to the other is 2.06 x 10¹² electrons

Explanation:

Given;

magnitude of the attractive force, F = 17 mN = 0.017 N

distance between the two objects, r = 24 cm = 0.24 m

The attractive force is given by Coulomb's law;

[tex]F = \frac{1}{4\pi \epsilon _0} \times \frac{Q^2}{r^2} = \frac{kQ^2}{r^2} \\\\Q^2 = \frac{Fr^2}{k} \\\\Q = \sqrt{ \frac{Fr^2}{k}} \\\\Q = \sqrt{ \frac{(0.017)(0.24)^2}{9\times 10^9}} \\\\Q = 3.298 \times 10^{-7} \ C[/tex]

The charge of 1 electron = 1.602 x 10⁻¹⁹ C

n(1.602 x 10⁻¹⁹ C) = 3.298 x 10⁻⁷

[tex]n = \frac{3.298 \times 10^{-7}}{1.602 \times 10^{-19}} = 2.06 \times 10^{12} \ electrons[/tex]

Therefore, the number of electrons transferred from one ball to the other is 2.06 x 10¹² electrons

Answer:

Food, clothes, language, and belief

Answer:

[tex]a_2=3.88m/s^2[/tex]

Explanation:

From the Question we are told that:

Initial Mass [tex]m_1=1300kg[/tex]

Final mass [tex]m_2=1300+400=>1700kg[/tex]

[tex]a_1=3.0m/s^2[/tex]

Generally the equation for  Force  is mathematically given by

 [tex]F=m_1a_1[/tex]

 [tex]F=1300*5[/tex]

 [tex]F=6500N[/tex]

Generally the equation for Final acceleration  is mathematically given by

 [tex]F'=m_2*a_2[/tex]

 [tex]a_2=\frac{6500}{1700}[/tex]

 [tex]a_2=3.88m/s^2[/tex]

Answer:

The velocity of the canoe relative to the river is 0.385 m/s, S37.26⁰W

Explanation:

Given;

velocity of the canoe relative to the earth, [tex]V_{r/e} = 0.33 \ m/s[/tex]

velocity of the river relative to the earth, [tex]V_{r/e} = 0.54 \ m/s[/tex]

The velocity of the canoe relative to the river is calculated as;

[tex]V_{(c/r)x} = V_{(c/e)x}- V_{(r/e)x} \ \ ----(1)\\\\V_{(c/r)y} = V_{(c/e)y}- V_{(r/e)y} \ \ ----(2)[/tex]

The x - component of the velocity of the canoe relative to the earth;

[tex]V_{(c/e)x} = 0.33 \times cos \ 45^0\\\\V_{(c/e)x} = 0.2333 \ m/s[/tex]

The y-component of the velocity of the canoe relative to the earth;

[tex]V_{(c/e)y} = 0.33 \times sin \ 45^0\\\\V_{(c/e)y} = 0.2333 \ m/s[/tex]

Note: velocity of the river relative to the earth has only x-component = 0.54 m/s

Apply equation (1) and (2) to calculate the velocity of the canoe relative to the river;

[tex]V_{(c/r)}x = 0.2333 - 0.54 = -0.3067 \ m/s\\\\V_{(c/r)}y = 0.2333 - 0 = 0.2333 \ m/s\\\\The \ resultant \ velocity;\\\\V_{c/r} = \sqrt{(-0.3067)^2 + (0.2333)^2} \\\\V_{c/r} = 0.385 \ ms/\\\\The \ direction:\\\\\theta = tan^{-1} (\frac{0.2333}{0.3067} ) = 37.26^0 \ south \ west \ of \ the \ river[/tex]

Answer:

h = 90.10 m

Explanation:

Given that,

A man is standing near the edge of a cliff 85 meters high, h₀ = 85 m

The initial speed of the stone, u = 10 m/s

The path followed by the projectile is given by :

[tex]h(t)=-4.9t^2+10t+85[/tex] ....(1)

For maximum height,

Put dh/dt = 0

So,

[tex]\dfrac{dh}{dt}=-9.8t+10=0\\\\t=\dfrac{10}{9.8}\\\\=1.02\ s[/tex]

Put the value of t in equation (1).

[tex]h(t)=-4.9(1.02)^2+10(1.02)+85\\\\=90.10\ m[/tex]

So, the maximum height of the stone is equal to 90.10 m.

Answer:

As the number of free electrons increases, the resistance of this type of non-metallic material decreases with increasing temperature.

Explanation:

Answer:

the tension in the tightrope is 233.68 N

Explanation:

Given the data in the question;

Time taken to reach the opposite tower t = 0.9 s

Distance between the two towers S = 26 m

mass per one meter length =  0.28 kg

First we calculate the velocity;

Velocity V = Distance / time

we substitute

Velocity V = 26 m / 0.9 s

Velocity V = 28.889 m/s

We know that Velocity V can also be expressed as;

V = √( T / m )

we make T the subject of formula

V² = T / m

T = mV²

we substitute

T = 0.28 × ( 28.889 )²

T = 233.68 N

Therefore,  the tension in the tightrope is 233.68 N

Answer:

The fish gobbles the mosquito at height 18 cm.

Explanation:

Initial velocity, u = 3.7 m/s

horizontal distance, d = 28 cm

Angle, A = 39 degree

Let the time is t.

Horizontal distance = horizontal velocity x time

d =  u cos A x t

0.28 = 3.7 cos 39 x t

t = 0.097 s

Let the height is h.

Use the second equation of motion

[tex]h =u t-0.5 gt^2\\\\h= u sin A t - 0.5 gt^2\\\\h= 3.7 sin 39 \times 0.097 - 0.5\times 9.8\times 0.097\times0.097\\\\h =0.226 -0.046 \\\\h=0.18 m=18 cm[/tex]

Answer:

The bird appears farther

Explanation:

This is because as the light from the bird travels into the water which has a higher refractive index than air, light rays from the kingfisher bird bend towards the normal at the water surface and thus enter the eye of the scuba diver. Now, if we project the light rays from the eyes of the scuba diver into the air, we see that they appear to come from a point farther than that of the actual kingfisher bird perched on the branch.

So, the bird appears to the diver to be farther from the surface than the actual bird

Answer:

Option (a).

Explanation:

Let the angular velocity is w.

The centripetal acceleration is given by

[tex]a = r w^2[/tex]

where, r is the distance between the axle and the spoke.

So, more is the distance more is the centripetal acceleration.

(a) For the points on the spoke closer to the hub than for points closer to the rim is larger distance, so the centripetal force is more.

The statement is true.  

(b) The direction of centripetal acceleration is always towards the center, so the statement is false.

(c) It is false.

(d) It is false.

Option (a) is correct.

Answer: 1 cal is 4.186 J, 1 kcal = 4186 J   A : 1014 m , B  200 m

Explanation:   A) Work done by climber is change in potential energy.

W = ΔEp = mgh = 67.0 kg· 9.81 m/s²· h = 160 kcal · 4186 J / kcal.

Solve h  =  160 kcal · 4186 J / kcal /67.0 kg· 9.81 m/s² = 1014 m

B  Energy is only 20 %  :   Then  h  =  0.20 ·160 kcal · 4186 J / kcal /67.0 kg· 9.81 m/s² = 200 m.

Actually, muscles also produce heat from most of the energy provided by food.

Answer:

3.83×10¯⁴ N

Explanation:

From the question given above, the following data were obtained:

Charge 1 (q₁) = +2.4x10¯⁸ C

Charge 2 (q₂) = +1.8x10¯⁶ C

Distance apart (r) = 1.008 m

Electrical constant (K) = 9×10⁹ Nm²/C²

Force (F) =?

The magnitude of the electrical force acting between the two charges can be obtained as follow:

F = Kq₁q₂ / r²

F = 9×10⁹ × 2.4x10¯⁸ × 1.8x10¯⁶ / (1.008)²

F = 0.0003888 / 1.016064

F = 3.83×10¯⁴ N

Thus the magnitude of the electrical force acting between the two charges is 3.83×10¯⁴ N

Answer:

The area directly above the light bulb is warmest because of convection.

Explanation:

if all the sides of the bulb are equally close to the light source inside the bulb, all area of the bulb would be equally heated by conduction. however, convection heating mainly heats up the surface above the light source. in convection heating, the air above the surface of the light source get heated by the light source and expands, casuing it to be less dense and rise to the top of the bulb. colder denser air at the top of the bulb sink to the light source adn gain heat and expands, becoming less dense. this process repeats and the surface above the light source becomes the warmest due to convection heating

Answer:

No. D is the right answer

Answer:

nonmental

Explanation:

Option B is correct. The substance floats and reacts violently with the water. Based on this Information, metal is the unknown substance.

A metal, a glossy substance that transmits electricity and heat reasonably efficiently when newly manufactured, polished, or broken.

Metals are either malleable or ductile. Metals can be chemical elements like iron.

Metal is  substance floats and reacts violently with the water. When particles collide, energy is transferred. A change in temperature can be used to identify this.

The substance floats and reacts violently with the water. Based on this Information, metal is the unknown substance.

Hence, option B is correct.

To learn more about metal, refer to the link;

https://brainly.com/question/18153051

#SPJ2

Answer:

by the drag force, 2.4004512 × 10⁻⁵ J is added to the air.

Explanation:

Given the data in the question;

drag coefficient of Cd = 1.4

speed v = 6.0 m/s

One model expands to a square 1.8 mm on a side

Area A = 1.8 × 1.8 = 3.24 mm² = 3.24 × 10⁻⁶ m²

distance travelled s = 240 mm = 0.24 m

we know that; density of air e = 1.225 kg/m³

Now,

Dragging force F[tex]_D[/tex] = ( Cd × e × v² × A  ) / 2

thermal energy = F[tex]_D[/tex] × s

so

thermal energy = ( 1.4 × 1.225  × (6)² × (3.24 × 10⁻⁶) × 0.24  ) / 2

thermal energy = ( 4.8009024 × 10⁻⁵ ) / 2

thermal energy = 2.4004512 × 10⁻⁵ J

Therefore,  by the drag force, 2.4004512 × 10⁻⁵ J is added to the air.