Is work being done on a barbell when a weight lifter is holding the barbell
over his head?

Answer:

52.802

Explanation:

"Significant figures" in Mathematics refer to the digits that give accuracy to the value of a measurement. There are specific rules when it comes to determining the significant figures. For example, all non-zero digits are considered significant and zeroes located in-between non-zero numbers are significant. In the number given above, the digit "0" is located between "8" and "1," therefore, it is significant. All the digits above are significant.

The problem is only asking for "five" significant figures. We can do this by counting from the left to the right. By this means, we know that the number will be rounded off to the nearest thousandths, which is "1." The number after 1 is 5, which means that 1 digit will be added to number 1, thus, making the digit into "2." The last digit (5) will then be removed.

Explanation:

five significant of 52.8015=52.801 ..

Answer:

4200 J/°C/kg

Explanation:

The formula for heat transfer is given by :

Q= m*c*ΔT  where;

Q= heat transferred = 6930 J

m=mass of the liquid = 0.330 kg

c= specific heat capacity=?

ΔT = 25-20 = 5.0°C

Applying the values in the formula as;

Q= m*c*ΔT

6930 = 0.330 * c * 5

6930 = 1.65 c

6930/1.65 = c

4200 = c

c= 4200 J/°C/kg

Answer:

B is the difference قصدي لا انا اعرف بشير بس ما اعرف اخوه يعني *قصدي لا انا اعرف بشير بس ما اعرف اخوه يعني *قصدي لا انا اعرف بشير بس ما اعرف اخوه يعني *قصدي لا انا اعرف بشير بس ما اعرف اخوه يعني *قصدي لا انا اعرف بشير بس ما اعرف اخوه يعني *

Answer:

I think the first two one is 70 the second on is 14

I hope this helps if I’m wrong I’m sorry

Explanation:

Answer:

A. The expected electricity bill for this month is Rs 18,896.2

B. The item which consumed the most energy during the month is the electric cooker with a total consumption of 1,110Kw/Month

Explanation:

Step 1 - Identify electrical appliances

I only have 8 electrical appliances in my home.

Step 2 - Assign usage per hour and calculate wattage used /month

Step 3 - Add up all the Kw used per month and multiply by the cost of 1 Kw

Total Kilowatt Consumed/Month = 1110 +108+120+10+84.6+421.2+29.7+6.12

= 1,889.62Kw/Month

Total cost of energy consumed per month = 1889.62 * Rs 10

= Rs 18,896.2

Cheers!

Answer:

28.1 m/s

Explanation:

[tex]u_x[/tex] = Initial velocity of the fish = 1.52 m/s

y = Height of the bird = 40 m

[tex]a_y[/tex] = Acceleration in y axis = [tex]9.81\ \text{m/s}^2[/tex]

[tex]u_y[/tex] = Initial velocity in y axis = 0

[tex]y=u_yt+\dfrac{1}{2}a_yt^2\\\Rightarrow 40=0+\dfrac{1}{2}\times 9.81t^2\\\Rightarrow t=\sqrt{\dfrac{40\times 2}{9.81}}\\\Rightarrow t=2.86\ \text{s}[/tex]

[tex]v_y=u_y+a_yt\\\Rightarrow v_y=0+9.81\times 2.86\\\Rightarrow v_y=28.057\ \text{m/s}[/tex]

The final velocity in x direction will remain the same as the initial velocity as there is no acceleration in the x direction [tex]u_x=v_x=1.52\ \text{m/s}[/tex]

Resultant velocity is given by

[tex]v=\sqrt{v_x^2+v_y^2}\\\Rightarrow v=\sqrt{1.52^2+28.057^2}\\\Rightarrow v=28.1\ \text{m/s}[/tex]

The fish is moving at a velocity of 28.1 m/s when it hits the water.

Answer:

The amount of water vapor in the air is 90% of what the air can hold.

Explanation:

The answer is A

Answer: The answer is B: The amount of water vapor in the air is 90% of what the air can hold      

Answer:

The true statements are;

The median of A is the same as the median of B

The interquartile range of B is greater than the interquartile range of A

Explanation:

The given parameters are;

The set of the number of runs, A = {1, 4, 2, 2, 3, 1, 1, 2, 1}

The number of runs the pitcher allows in the tenth game = 9 runs

The set of the number of runs allowed in 10 games B = {1, 4, 2, 2, 3, 1, 1, 2, 1, 9}

Rearranging the data, we get  

A = 1, 1, 1, 1, 2, 2, 2, 3, 4

B = 1, 1, 1, 1, 2, 2, 2, 3, 4, 9

For the set A, we have;

Q₁ = 1, Q₂ = 2, Q₃ = 2

Therefore, the interquartile range of A = Q₃ - Q₁ = 2.5 - 1 = 1.5

For the set B, we have;

Q₁ = 1, Q₂ = 2, Q₃ = 2

Therefore, the interquartile range of A = Q₃ - Q₁ = 3.25 - 1 = 2.25

Therefore, the correct answers with regards to the two data are;

The median of A is the same as the median of B

The interquartile range of B is greater than the interquartile range of A

Answer:

blood picks up waste products such as carbon dioxide

returns to right atrium

moves to right ventricle and to lungs

blood travels from the lungs to the left atrium

carries oxygen and nutrients to the body cells

Explanation:

In the circulatory system, the blood carries the carbon dioxide to the right atrium of the heart through superior vena cava, then it move to right ventricle through tricuspid valve. The blood move to lungs following pulmonary artery and from lungs blood travels to the left atrium. From left atrium blood moves to the rest of the body through aorta and carries oxygen and nutrients to the whole body cells through.

Hence, the correct order is as follows:

blood picks up waste products such as carbon dioxide

returns to right atrium

moves to right ventricle and to lungs

blood travels from the lungs to the left atrium

carries oxygen and nutrients to the body cells

Answer:

The acceleration caused by a net force of 2 N on a 2 kg mass is 1 m/s²

Explanation:

The given parameters on an applied force is as follows;

The acceleration given to a 1 kg mass by a 1-N net force = 1 m/s²

According to Newton's second law of motion, the acceleration, "a", given to an object by a force, "F", is proportional to the magnitude of the net force

Therefore, we have;

F ∝ a

The constant of proportionality is given as the mass, "m", of the object, therefore, we have;

F = m × a

The acceleration given to a 2 kg mass by a 2-N net force is given therefore, given as follows;

2 N = 2 kg × a

a = 2 N/(2 kg) = 1 m/s²

The acceleration, "a", caused by a net force of 2 N on a 2 kg mass is a = 1 m/s².

Explanation:

W=f×d

=20×6

w=120 joule

Answer:

a) 1.55 m/s

b) 2.3 m/s

Explanation:

We know that the boat travels across the river, if we define the river as the x-axis, then the velocity of the boat is only on the y-axis.

Then we can write the velocity of the boat in still water as:

S = (0, B)

Now, when the boat is on the river, the velocity of the boat will be equal to the velocity of the boat in still water plus the velocity of the river.

The velocity of the river is:

v = (R, 0).

Then the velocity of the boat in that river is:

V' = (0, B) + (R, 0) = (R, B)

Now, we know that the velocity of the boat is 10km/h, and it travels at an angle of 34° with respect to the shore.

We can use the Pythagoreans theorem to write the components of this velocity as:

x-axis component = 10km/h*cos(34°) = 8.29 km/h

y-axis component = 10km/h*sin(34°) =  5.59 km/h

Then the velocity of the boat can be written in components as:

velocity = ( 8.29 km/h,  5.59 km/h)

And we knew that the velocity of the boat was written as  (R, B)

Then we must have:

R = 8.29 km/h

B = 5.59 km/h

a) The speed of the boat in m/s:

We know that the speed of the boat is 5.59 km/h.

First, we know that:

1km = 1000m, then:

5.59 km/h = 5.59*(1000m)h = 5,590 m/h

And we know that:

1h = 3600s

Then we can write:

5,590 m/h = 5,590 m/(3600s) = 1.55 m/s

b) The speed of the river in m/s:

We know that the speed of the river is 8.29 km/h

Using the same reasoning as above, we can do the change of units as follows:

8.29 km/h = 8.29 (1000m)/(3600s) = 2.3 m/s

Answer:

d = 4[m]

Explanation:

Torque in physics is defined as the product of force by distance. This way you can use the following equation to calculate the torque.

[tex]T=F*d[/tex]

where:

T = torque [N*m]

F = force [N]

d = distance [m]

Now replacing in the equation above.

[tex]84=21*d\\\\d= 4[m][/tex]

Answer:

4 target heart rate. is the answer

Explanation:

hope its right

Answer:

1.0125 x 10^19

Explanation:

current flowing through conductive wire= 9mA = 9 x 10^ -3 A

charge passing per 3 min

Q = It

= 9 x 10^ -3 x (3 x 60)

= 1.620 C

no of electrons in charge

Q = ne

1.620 = n x 1.6 x 10 ^ -19

n. = 1.0125 x 10 ^19

Explanation:

Lola

Or Jasmine

Or lucy

Or Nightingale

Or Sugarcane

Or Polly

Or Heather

Some names I like!

Answer:

Explanation:

V_{1} = first volume

V_{2} = second volume

T_{1} = first temperature

T_{2} = second temperature

element z are isotopes because number of netron are different and number of protons are same

Answer:

299,792,458 m/s = speed of light

Explanation:

Answer:

elements

not really an explanation

Answer:

The horizontal distance traveled by the skydiver is 510.8 m.

Explanation:

Given;

height of fall, h = 800 m

initial velocity of the airplane, u = 40 m/s

The time to fall to the ground is calculated as;

[tex]t = \sqrt{\frac{2h}{g} } \\\\t = \sqrt{\frac{2 \times 800}{9.81} }\\\\t = 12.77 \ s[/tex]

The horizontal distance or range of the motion is calculated as;

R = ut

R = 40 m/s x 12.77 s

R = 510.8 m

Therefore, the horizontal distance traveled by the skydiver is 510.8 m.

Answer:

A. when the Sun, Moon and Earth are in a straight line

Explanation:

The highest tide is formed when the sun, moon, and also the earth are in alignment. This high tide is known as spring tides.

Spring tides happen when we have a new moon or a full moon. With the earth, sun and moon aligning. We have lunar and solar tide forming a reinforcement with each other causing high tides or extreme tides. we have collectively, their gravitational pull on water of the earth to become stronger

Answer:

The change in velocity is 5.5 km/h

Explanation:

The initial velocity with which the sailboat is travelling, v₁ = 10 km/h

The final velocity with which the sailboat is travelling, v₂ = 15.5 km/h

The change in velocity, Δv, is the difference between final velocity, v₂ and the initial velocity, v₁, as follows;

Mathematically, Δv = v₂ - v₁

By substituting the given values, we have;

Δv = 15.5 km/h - 10 km/h = 5.5 km/h

The change in velocity, of the sailboat Δv = 5.5 km/h.

Answer:

The index of refraction varies with frequency or color. Frequency does not change as light travels from one medium to another.

Explanation:

Green light has a higher refractive index than orange light for the same material because orange color has a higher wavelength than green light and if the wavelength of light increases the refractive index decreases.

The distance between two identical locations (adjacent crests) in successive cycles is known as the wavelength, and it is used to describe waveform signals that are transmitted over wires or into space. Typically, in wireless systems, this length is specified in meters (m), centimeters (cm), or millimeters (mm). The wavelength is more frequently described in nanometers (nm), which are units of 10-9 m, or angstroms, which are units of 10-10 m, for infrared (IR), visible light (UV), and gamma radiation.

Frequency, which is defined as the number of wave cycles per second, and wavelength have an inverse relationship. The wavelength of a signal decreases with increasing frequency, or we can say that wavelength and refractive index are inversely proportional to each other.

To get more information about Wavelength :

https://brainly.com/question/13533093

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Answer:

2.5m/s²

Explanation:

Given parameters:

Mass of car  = 1400kg

Resultant force  = 3500N

Speed  = 30m/s

Unknown:

Average acceleration = ?

Solution:

According to the Newton's second law of motion:

     Force  = mass x acceleration

Now;

       3500 = 1400 x acceleration

      Acceleration  = [tex]\frac{3500}{1400}[/tex]   = 2.5m/s²

Answer:

25 km/h

Explanation:

speed=distance÷time

125÷5=speed

125÷5=25 (then add units)

Answer:

W= F × d

W= 2kn × 3.6

W= 7.2 J

Work is measured in Joules!

Answer: A negatively-charged ion always has more electrons than protons

Explanation:

First, we know that the elementary negative charge is the electron, while the positive one is the proton. Such that both have the same charge in magnitude, but a different sign. Such that if we have the same number of electrons and protons in an atom, the charge of this atom will be neutral.

And an ion is an atom with a different number of electrons and protons, so the charge of the atom is not neutral.

Then if we have a negatively-charged ion, the charge of this atom is negative. Then we must have a larger number of electrons (the negative ones) than protons (the positive ones)

Then the correct option is:

A negatively-charged ion always has more electrons than protons