Given that o.2i+bj+o.4k is a unit vector,what is the value of b?

Answer:

8.37 Joules

Explanation:

The amount of energy that a substance, such as animal tissue or rubber can take and yet return to its original condition is known as resilience. When we stress such a substance and then let it restore to its previous state, we are referring to the substance to maintain its elastic area of the stress-strain curve.

From the given information:

the resilence is 0.93

The amount of work done during stretching of the tendon = 9.00 J

Thus,

the work done when relaxing = 0.93 × 9.00 J

= 8.37 Joules

Answer:

pretty sure its A

Explanation:

please give brainliest if i'm correct

Answer:

A.

Explanation:

I have done this and that was correct

hope this helps

Explanation:

the unit of area is called a derived unit because it is made of two fundamental unit metre and metre.

Answer:

[tex]f_n=3.75N[/tex]

Explanation:

From the question we are told that:

Frictional force [tex]F=0.150N[/tex]

Coefficient of kinetic friction [tex]\mu=0.04[/tex]

Generally the equation for Normal for is mathematically given by

 [tex]f_n=\frac{F}{\mu}[/tex]

Therefore

 [tex]f_n=\frac{0.150}{0.04}[/tex]

 [tex]f_n=3.75N[/tex]

Answer: The period of a spring if it has a mass of 5 kg and a spring constant of 6 N/m is 5.73 sec.

Explanation:

Given: Mass = 5 kg

Spring constant = 6 N/m

Formula used to calculate period is as follows.

[tex]T = 2 \pi \sqrt\frac{m}{k}[/tex]

where,

T = period

m = mass

k = spring constant

Substitute the values into above formula as follows.

[tex]T = 2 \pi \sqrt\frac{m}{k}\\= 2 \times 3.14 \times \sqrt\frac{5}{6}\\= 5.73 s[/tex]

Thus, we can conclude that the period of a spring if it has a mass of 5 kg and a spring constant of 6 N/m is 5.73 sec.

Answer:

when we get images from the telescope, we're not seeing those object like they are right now. we're seeing them like they looked when that light left those distant objects...... the animation cuts to a visualization of distant galaxies imaged by Hubble.

Answer:

ok

Explanation:

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Answer: (d)

Explanation:

Given

Mass of object [tex]m=2\ kg[/tex]

Speed of object [tex]u=5\ m/s[/tex]

Mass of object at rest [tex]M=3\ kg[/tex]

Suppose after collision, speed is v

conserving momentum

[tex]\Rightarrow mu+0=(m+M)v\\\\\Rightarrow v=\dfrac{2\times 5}{2+3}\\\\\Rightarrow v=2\ m/s[/tex]

Initial kinetic energy

[tex]k_1=\dfrac{1}{2}\times 2\times 5^2\\\\k_1=25\ J[/tex]

Final kinetic energy

[tex]k_2=\dfrac{1}{2}\times (2+3)\times 2^2\\\\k_2=10\ J[/tex]

So, it is clear there is decrease in kinetic energy . Thus, energy decreases and velocity becomes 2 m/s.

Answer:

Explanation:

one electron has [tex]1.60217662*10^{-19}~coulombs~then\\\\1.02*10^{20}~electrons------->1.02*10^{20}*1.60217662*10^{-19}~coulombs= 16.3422~coulombs[/tex]

Answer:

cause they give u milk

Explanation:

Answer:

Cows are important as they provide humans many things for survival. They provide milk, meat, and leather, all of these are important resources.

Answer:

A. bends towards the Equator.

Explanation:

Rossby waves are inertial waves that are naturally occurring in a rotating fluids. These waves are also called as the planetary waves.

The Rossby waves are undulated that occur in the polar front jet stream when there is a significant differences in the temperatures between the polar and the tropical air masses.

It occurs when the polar air masses moves towards the equator and when the tropical air masses moves towards the pole.  It is formed when the air bends away from the poles and bends towards the equator.

Hence the correct option is (A).

Answer:

The amount of heat required to boil away 1 kg of water is 10 times the amount of heat required to melt 1 kg of ice

Explanation:

let the latent heat of fusion of ice  = L

then, the latent heat of vaporization of water = 10L

The heat of fusion of 1 kg of ice = 1 x L = L

The heat of vaporization 1 kg of water = 1 x 10L = 10L

Therefore, the amount of heat required to boil away 1 kg of water is 10 times the amount of heat required to melt 1 kg of ice

Answer:

400

Explanation:

Answer:

In "Young Goodman Brown," Hawthorne reveals his feelings about his Puritan ancestors when the dark man reveals that he helped Brown's forebears persecute others.

Explanation:

hey mate i know it is right so don't worry this is the correct

Answer:

In "Young Goodman Brown," Hawthorne reveals his feelings about his Puritan ancestors when the dark man reveals that he helped Brown's forebears persecute others. so that means the answer is D.

Explanation:

A. brown strives to resist his dark mission

B. faith expresses her anxieties about young brown's departure

C. brown discovers his catechism teacher is on speaking terms with the devil

D. the dark man reveals that he helped brown's forebears persecute others(correct answer)

Answer:

b) 1 m/s

I am sure...........

Answer:

66.83 meters

Explanation:

After a quick online search, it seems that scientists calculate the average reaction time of individuals as 2.3 seconds between seeing an obstacle and putting their foot on the brakes. Now that we have this reaction time we need to turn the miles/hour into meters/second.

1 mile = 1609.34 meters  (multiply these meters by 65)

65 miles = 104,607 meters

1 hour = 3600 seconds

Therefore the car was going 104,607 meters every 3600 seconds. Let's divide these to find the meters per second.

[tex]\frac{104,607}{3600} = \frac{29.0575 meters}{1 second}[/tex]

Now we simply multiply these meters by 2.3 seconds to find out the distance covered before the driver puts his/her foot on the brakes...

29.0575m * 2.3s = 66.83 meters

Answer:

The hydrogen peroxide decomposes as: [tex]H_2O_2\rightarrow 2H_2O+O_2[/tex]

Explanation:

Hydrogen peroxide antiseptic although tightly capped but left on the shelf for a long time leads to swollen bottle and opens with a hissing sound because hydrogen peroxide reacts with air in presence of light to dissociate into water and oxygen molecules that leads to high volume of content in the tightly closed bottle and formation of water molecules from hydrogen peroxide.

Once the hydrogen peroxide has turned into water molecules it is no longer effective as an antiseptic.

Answer:

Light-year is the distance light travels in one year. Light zips through interstellar space at 186,000 miles (300,000 kilometers) per second and 5.88 trillion miles (9.46 trillion kilometers) per year.

Explanation:

Answer:

1.2 x 10^-12

Explanation:

3/2.5 x 10^-6/10^6

1.2 x 10^-6 x 10^-6

1.2 x 10^-12

Answer:

d.it is used in electronic devices

Explanation:

Given that,

The mass of a car, m₁ = 1332 kg

The speed of the car, u₁ = 25 m/s (right)

The mass of a truck, m₂ = 3000 kg

The speed of the truck, u₂ = -15 m/s

The total momentum after the crash is given by :

p=m₁u₁ + m₂u₂

Put all the values,

P = 1332(25) + 3000(-15)

= −11700 kg-m/s

So, the total momentum after the crash is equal to 11700 kg-m/s and it is in the left direction.

Explanation:

the efficiency of a machine can be increased by reducing the friction

please mark the brainliest

Answer:

a. At a distance greater than r

b. T_m is greater than T_e.

Explanation:

a. Two identical satellites orbit the earth in stable orbits. One satellite orbits with a speed vat a distance r from the center of the earth. The second satellite travels at a speed that is less than v. At what distance from the center of the earth does the second satellite orbit?

Since the centripetal force on any satellite, F equals the gravitational force F' at r,

and F = mv²/r and F' = GMm/r² where m = mass of satellite, v = speed of satellite, G = universal gravitational constant, M = mass of earth and r = distance of satellite from center of earth.

Now, F = F'

mv²/r = GMm/r²

v² = GM/r

v = √GM/r

Since G and M are constant,

v ∝ 1/√r

So, if the speed decreases, the radius of the orbit increases.

Since the second satellite travels at a speed less than v, its radius, r increases since v ∝ 1/√r.

So, the distance the second satellite orbits is at a distance greater than r

b. An identical satellite is orbiting the moon at the same distance with a speed v_m. How does the time T_m it takes the satellite circling the moon to make one revolution compare to the time T_e it takes the satellite orbiting the earth to make one revolution?

Since the speed of the satellite, v = √GM/r where M = mass of planet

Since the satellite is orbiting at the same distance, r is constant

So, v ∝ √M

Since mass of earth M' is greater than mass of moon, M", the speed of satellite circling moon, v_m is less than v the speed of satellite circling earth at the same distance, r

Now, period T = 2πr/v where r = radius of orbit and v = speed of satellite

Since r is constant for both orbits, T ∝ 1/v

Now, since the speed of the speed of the satellite on earth orbit v  is greater than the speed of the satellite orbiting the moon, v_m, and T ∝ 1/v, it implies that the period of the satellite orbiting the earth, T_e is less than the period of the satellite orbiting the moon, T_m since there is an inverse relationship between T and v. T_e is less T_m implies T_m is greater than T_e

So, T_m is greater than T_e.

Answer:

Because weight W = M g, the ratio of weights equals the ratio of masses.

(M_m g)/ (M_w g) = [ (p^2 Man )/ (2 K_man)] / [ (p^2 Woman )/ (2 K_woman)

but p's are equal, so

K_m/K_m = (M_w g)/(M_m g) = W_woman / W_man = 450/680 = 0.662Explanation:

Answer:

the required speed with which the missile move relative to the Earth is -0.727c

Explanation:

Given the data in the question;

relative velocity relation;

u' = u-v / 1 - [tex]\frac{uv}{c^2}[/tex]

so let V[tex]_B[/tex] represent the velocity as seen by an external reference frame; u=V[tex]_B[/tex]

and let V[tex]_A[/tex] represent the speed of the secondary reference frame; v=V[tex]_A[/tex]

hence, u' is the speed of B as seen by A

so

u' = V[tex]_B[/tex]-V[tex]_A[/tex] / 1 - [tex]\frac{V_BV_A}{c^2}[/tex]

now, given that; V[tex]_A[/tex] = 0.9c  and V[tex]_B[/tex]  = 0.5c

we substitute

u' = ( 0.5c - 0.9c ) / 1 - [tex]\frac{(0.5c)(0.9c)}{c^2}[/tex]

u' = ( 0.5c - 0.9c ) / 1 - [tex]\frac{c^2(0.5)(0.9)}{c^2}[/tex]

u' = ( 0.5c - 0.9c ) / 1 - (0.5 × 0.9)

u' = ( -0.4c ) / 1 - 0.45

u' = -0.4c / 0.55

u' = -0.727c

Therefore, the required speed with which the missile move relative to the Earth is -0.727c

Answer:

The Answer is D

Explanation:

Hope this helps!!!!

Answer:

there is no fluctuation in the measurement because the quantity of molecule is too large and a quantity of some molecules is imperceptible.

Explanation:

The pressure measurement is carried out by calibrating the force exerted by the air on a surface of known area, suppose a small area 1 mm² = 0.01 cm²

To find out if the random movement of air molecules affects the pressure reading, let's calculate the number of molecules that reaches the pressure gauge.

In a system at atmospheric pressure and in a volume of 1 m³ (walls of 1 m each) there is one mole of air molecules, this mole is evenly distributed, so how many molecules fall on our surface

           # _molecule = 6.02 10²³ 0.01 10⁻⁴ / 1

           #_molecular = 6.02 10¹⁷ molecules per second

therefore the variation of the number of molecules is not very important

Consequently there is no fluctuation in the measurement because the quantity of molecule is too large and a quantity of some molecules is imperceptible.

Answer:

the particles vibrate inside the tyre

Explanation:

as the car moves kinetic energy is transfered in the tyres which causes the particles to vibrate inside the tyre so the kinetic store is. transferred into thermal