A 70 kg man is running up the stairs which is 3m high in 2s.(a)How much work is done by the man?(b)What is the power exerted by the man? (Use g = 10ms 2)​

Answers

Answer 1

Explanation:

m = 70 kg

s = 3m

t =2s

g = 10 m/s²

(a)How much work is done by the man?

W = Fs

= mg X s

= 70 x 3 x 10

= 210 x 10

= 2100 Joule

(b)What is the power exerted by the man?

P = W/t

= 2100/2

P = 1050 Watt


Related Questions

A 2.98-kg object oscillates on a spring with an amplitude of 8.05 cm. Its maximum acceleration is 3.55 m/s2. Calculate the total energy.

Answers

Answer:

a = ω^2 A      formula for max acceleration (ignoring sign)

V = ω A         formula for max velocity

V^2 = ω^2 A^2 = a A   from first equation

E = 1/2 M V^2 = 1/2 * 2.98 * 3.55 * .0805 = .426 J

(kg * m/sec^2 * m = kg m^2 / sec^2 = Joule

What is the force exerted on a selectively permeable membrane because water has moved from an area of higher concentration to an area of lower concentration of water?
Diffusion
Facilitated transport
Osmotic pressure
Endocytosis

Answers

Question

what is the force exerted on a selectively permeable membrane beacuse water has moved from an area of higher concentration to an area of Lower concentration of water?

Answer

OSMOSIS

Explanation

Osmosis: This is the hydrostatic force acting to equalize the concentration of water on both sides of the membrane that is impermeable to substances dissolved in that water. Water will move along its concentration gradient.

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A device is rated at 1.3kW when connected to a 120 V source. The equivalent resistance of this device in ohm is:

a- 18.3
b- 12.0
c- 11.1
d- 14.4

Answers

Answer:

D.

correct me if im wrong

brainlest plsss<333

The 0.01 kg marble is dropped from rest at A through the smooth glass tube and accumulate in the basket at C as shown in Figure Q2(b). Determine: i) the velocity of the marble at B ii) the horizontal distance R of the basket from the end of the tube, and iii) the speed at which the marble falls into the basket.​

Answers

Crazy Wally Ok Ok ok hhahahaha

plz help ASAP I'll mark as brainliest ​

Answers

Hi there!

1.

Hooke's law states that:

F = -kx

k = Spring constant (N/m)

x = DISPLACEMENT from equilibrium (m)

Essentially, the force of a spring is PROPORTIONAL to its spring constant and its displacement from its equilibrium point.

2.

The force of the spring (T) is not proportional to the spring's length (l), but rather its DISPLACEMENT from its equilibrium length. (Δl)

3.

The equilibrium length is where the force of the spring (T) = 0N. Looking at the graph, the line intersects this value at l = 30cm.

4.

We can begin by looking at the given graph.

When the spring force = 4N, the total length of the spring is 35 cm.

Now, the EQUILIBRIUM length is 30 cm, so the total elongation is:

35 - 30 = 5 cm.

5.1.

If the spring elongates by 10 cm, the total length of the spring is:

30 + 10 = 40 cm

According to the graph, a length of 40 cm corresponds to a force of 8N.

5.2.

We can solve for the weight of the ball using the following:

W (weight) = m (mass) · acceleration due to gravity (10N/kg)

Using a summation of forces:

∑F = T - W

The elongation that we are solving for occurs at the equilibrium point (net force = 0 N), so:

0 = T - W

T = W = 8 N

5.3.

0 = T - Mg

T = Mg

Use the prior value of T and gravity to solve:

8 = 10M

m = 0.8 kg

Suppose you want to make the demonstration more dramatic by attracting as much hair as possible with the balloon. Which of the following is the best choice to accomplish your goal? A. Decrease the electric force by holding the balloon closer to the hair. B. Increase the electric force by rubbing the balloon for a longer period of time. C. Decrease the electric force by using a larger balloon. D. Increase the electric force by holding the balloon farther away from the hair.

Answers

Answer:

B. Increase the electric force by rubbing the balloon for a longer period of time.

Explanation:

25.Figure 22.22 shows a plot
of potential versus position
along the x-axis. Make a plot
of the x-component of the
electric field for this situation.

Answers

The relationship between the potential and the electric field allows to find the results for the value of the electric field as a function of the distance is:

In the attachment we see the graph of the electric field as a function of distance.

Electric potential is defined by the change in potential energy of a test charge between two points, between the value of the test charge.

          dV = - E . ds

          E = [tex]- \frac{dV}{ds} \ \hat s[/tex]  

Where the bold letters indicate vectors, V is the potential difference, E the electric field and s the path.

Let's apply this expression for each section of the given graph:

1) section from x₀ = 0 to x_f = 2 m, the potential is V₀ = 2 V is constant.

  The derivative of a constant is zero.

        E = 0

2) Section between x₀ = 2 and x_f = 4 m, the potential varies linearly from V₀ = 2 v to V_f = -2 V.

We look for the equation of the line.

       V-V₀ = m (x- x₀)

We carry out the derivative.

      E = - m i ^

The slope (m) is:

       [tex]m= \frac{V_f - V_o}{x_f- x_o}[/tex]  

Let's calculate.

       [tex]m= \frac{-2 -2}{4-2} = \ -2 \ V/m[/tex]  

Let's substitute.

       E =  [tex]2 \hat i \ V/m[/tex]  

         

3) From x₀ = 4 to x_f = 4.5 m, the potential varies from V₀ = -2 to V_f = 0.

We look for the equation of the line and we derive.

      E = - m i ^

Let's  substitute.

      [tex]m = \frac{0-(-2)}{4.5-4} = \ 4 V/m[/tex]  

    E = - 4 [tex]\hat i[/tex] V / m

4) From x₀ = 4.5 m to x_f = 6m.  The potential is constant and the derivative of a constant is zero.

      E = 0

5) From x₀ = 6m to x_f = 8 m, the potential changes linearly from v₀ = 0 to V_f = 1 V

We look for the equation of the line and we derive.

       E = - m i ^

       [tex]m = \frac{1-0}{8-6} = \ 0.5 \ V/m[/tex]  

      E = - 0.5 [tex]\hat i[/tex] V/m

6) From x₀ = 8m to x_f = 9m, the potential changes linearly from V₀ = 1 V to V_f = -1.

We look for the equation of the line and we derive.

       E = - m i ^

       [tex]m = \frac{-1-1}{9-8} = \ -2 \ V/m[/tex]

Let's substitute.

       E = 2 [tex]\hat i[/tex] V/m

7) From x₀ = 9m to x_f = 10 m, the potential changes linearly from V₀ = -1 V to V_f = -2 V

     

We look for the equation of the line and we derive.

       E = - m i ^

       [tex]m = \frac{-2+1}{10-9} = \ -1 \ V/m[/tex]

Let's substitute.

       E = 1 [tex]\hat i[/tex]  V/m

In the attachment we can see these Electric fields as a function of distance.

In conclusion, the relationship between the potential and the electric field we can find the results for the value of the electric field as a function of the distance is:

In the attachment we see the graph of the electric field as a function of distance.

Learn more about the electric field here:  brainly.com/question/14306881

stuck with this one. ​

Answers

Y is the right answer :)

4. If a charged body is negatively charged, it has excess of _______

Answers

Answer:

Electrons

Explanation:

Electrons are negatively charged sub-atomic particles, therefore when a body's negatively charged, it means that there's more electrons than protons.

In what way does Isaac represent us?

Answers

Answer:

I believe The Knowledge that we apply everyday or based on these methods and discoveries may represent us

Explanation:

A crate is released on a frictionless plank inclined at angle q with
respect to the horizontal. Which of the following relationships is true?
(Assume that the x-axis is parallel to the surface of the incline.)
a. Fy = Fg
c. Fy = Fx
b. Fx = 0
d. none of the above

Answers

None of the given options is correct based on the relationship for the components of the crate's weight.

The given parameter:

Angle of inclination, = q

The vertical component of the force on the crate is calculated as follows;

[tex]F_y = W \times cos(q)\\\\F_y = F_gcos(q)[/tex]

The horizontal component of the crate is calculated as follows;

[tex]F_x = F_g \times sin(q)\\\\F_x = F_g sin(q)[/tex]

Thus, we can conclude that none of the given options is correct based on the relationship for the components of the crate's weight.

Learn more about forces on inclined weight here:  https://brainly.com/question/11351170

What is the half-life of the imaginary element Lokium? Show your work

Answers

Answer:What is the half life of the element Lokium?

The half-live of the element Lokium is 4.

Explanation:

sorry if im wrong, have good day

Answer:

The half-life of the element Lokium is 4

What is half-life?

Whether or not a given isotope is radioactive is a characteristic of that particular isotope. Some isotopes are stable indefinitely, while others are radioactive and decay through a characteristic form of emission. As time passes, less and less of the radioactive isotope will be present, and the level of radioactivity decreases. An interesting and useful aspect of radioactive decay is the half-life. The half-life of a radioactive isotope is the amount of time it takes for one half of the radioactive isotope to decay. The half-life of a specific radioactive isotope is constant; it is unaffected by conditions and is independent of the initial amount of that isotope.

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Andy Petite pitches a 0.8 kg baseball with a velocity of 67 m/s. Josh Hamilton
hits the ball back at a velocity of -44 m/s. Determine the impulse Josh
Hamilton's bat delivered to the baseball and enter to the nearest kg-m/s with
the correct sign.

Answers

The Impulse delivered to the baseball is 89 kgm/s.

To solve the problem above, we use the formula of impulse.

⇒ Formula:

I = m(v-u)................. Equation 1

Where:

I = Impulse delivered to the baseballm = mass of the baseballv = Final velocity of the baseballu = initial speed of the baseball

From the question,

⇒ Given:

m = 0.8 kgu = 67 m/sv = -44 m/s

⇒ Substitute these values into equation 1

I = 0.8(-44-67)I = 0.8(-111)I = -88.8I ≈ -89 kgm/s

Note: The negative tells that the impulse is in the same direction as the final velocity and therefore can be ignored.

Hence, The Impulse delivered to the baseball is 89 kgm/s.

Learn more about impulse here: https://brainly.com/question/7973509

A 2.2 kg model rocket is shot straight up in the air from the ground, with an initial velocity of 36.4 m/s. The rocket reaches its maximum height, and falls back to the ground. What is the maximum height of the rocket? Round your answer to 2 decimal places.

Answers

Answer:

Explanation:

Ignoring friction, the initial kinetic energy will convert to maximum potential energy at its highest point.

PE = KE

mgh = ½mv²

    h = v²/2g

    h = 36.4²/ (2(9.81))

    h = 67.53109...

    h = 67.53 m

(c) It is suggested that one side of the copper sheet cools to a lower temperature than the
other side.
Explain why this does not happen.
[2]

Answers

Answer:

Explanation:

The word "sheet" implies that the copper is quite thin.

Copper is also a very good conductor of heat.

Therefore, with a very short heat flow distance to cover and a high rate of heat transmission, temperature differences on either side of the sheet are almost instantaneously eliminated by heat flow.

5. Layer of Earth consisting of crust & upper layer of mantle ________

Answers

Answer:

lithosphere

Explanation:

hope this helps you!!

You are pulling a sled with a constant velocity using a rope held horizontally in
the snow. Using a spring scale attached to the rope, you measure the tension
to be 0.96 N. The sled's mass is 0.58 kg. Write the surface force the ground
exerts on the sled in component form, and determine its magnitude.

Answers

Answer:

Explanation:

if you are pulling in the positive direction and Upward is also positive.

F = -0.96i + 0.58(9.8)j

F = -0.96i + 5.7j

F = √(-0.96² + 5.7²) = 5.8 N

You are pulling a sled with constant velocity by using a rope then the surface force the ground exerts on the sled will be 5.8 N.

What is tension?

The pulling force conveyed axially by a string, cable, chain, or another analogous object, or by either end of a rod, truss member, or another such three-dimensional object, is referred to as tension in physics. Another way to think of tension is as the action-reaction pair of forces acting at each end of the previous elements. Perhaps tension is the polar opposite of compression.

A restoring force may cause what is also referred to as tension when atoms or molecules are torn apart from one another at the atomic level and build up potential energy.

If you are moving upward and pushing in a positive way,

F = -0.96 i + 0.58(9.8) j

F = -0.96 i + 5.7 j

F = [tex]\sqrt{(-0.96^2 + 5.7^2)}[/tex]

F= 5.8 N

To get more information about Tension :

https://brainly.com/question/15880959

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Which is the independent variable in the graph of the U.S. population 1800-1900?

1. United States
2. straight lines
3. years
4. population

Answers

Answer:

3. years

Explanation:

The independent variable is the x axis of graph

an object is traveling with a constant velocity of 5m/s. How far will it have gone after 7s

Answers

Answer:

35m/s

Explanation:

Answer:

35m/s

Explanation:

Simply multiply 5 and 7.

i need help with the problem below

Answers

Answer:

Explanation:

a) F = ma

a = F/m

a = 9(800) / 1 x 10⁹ = 7.2 x 10⁻⁶ m/s

b) t = v/a

t = 200 / 7.2 x 10⁻⁶

t = 2.8 x 10⁷ s       about 10½ months

c) v² = u² + 2as

s = (v² - u²) / 2a

s = (200² - 0²) / (2( 7.2 x 10⁻⁶))

s = 2.8 x 10⁹ m    nearly 7 times around the earth

And all this assumes NO FRICTION.


What effect does the time taken to lift the mass have on power output?

Answers

The longer the time taken, the lower the power output.

This is since power is calculated through

Energy transferred / time

Increasing the denominator will lead to a lower value overall

A small ball with a mass of 0.6 kg and a velocity of 12 m/s hits another ball with the same mass. The firs forward and hits a third ball with a mass of 0.2 kg. If the system is closed, what is the velocity of the third ball?

4 m/s

36 m/s

30 m/s

1.44 m/s​

Answers

I think is 30m/s I am not sure

Write down the condition required for the thermonuclear fusion.​

Answers

Answer:

The main condition necessary for a controlled thermonuclear fusion:

The ions must be held together in close proximity at high temperature with a confinement time long enough to avoid cooling.

Someone help me please !!!! Will mark Brianliest !!!!!!!!!!!!!!!!

Answers

Strain it , the sand didn’t dissolve in the solution it just settled in the bottom

Answer:

Decant it.

Explanation:

Pour the water/sugar solution off the sand. When the sand wants to start coming out as well, Stop and add fresh water to the beaker, stir to rinse the remaining solution into a less concentrated solution and decant again.

Repeat the dilution process until the mix is essentially sand and water, then drive the remaining water from the sand by drying.

explain how water erosion changes land forms

Answers

Answer:

Water erosion can slowly wash away dirt and rocks, wearing away landforms and sometimes forming rivers that can even carve out stone over time.

Using the formula below, calculate the kinetic energy of the 6 gram stone going 10 Mph
going 10 mph
KE = 1/2 Mass x Speed?
=

Answers

Answer:

Explanation:

A wonderful (NOT) mixed unit problem

convert mph to m/s

v = 10 mi/hr(5280 ft/mi)(12 in/ft)(2.54 cm/in) / (100 cm/m) / (3600 s/hr)

v = 4.4704 m/s

KE = ½(0.006)4.4704²

KE = 0.05995342848 J

KE = 0.06 J

Explain how the removal of heat energy affects the speed of the particles in a substance

Answers

Answer:

The removal of heat energy slows the speed of particles

Explanation:

When you add heat to a substance, the heat energy gets transferred to kinetic energy, and the molecules began to move a greater distance at a greater speed. When you remove heat, the opposite happens.

objects want to ______ ___________ doing what they're __________ ____________ because they are "lazy." This is called __________.

Answers

Answer:

Explanation:

Objects want to continue doing what they're already doing because they are "lazy." This is called inertia.

is xenon a pure substance​

Answers

[tex]\large\huge\green{\sf{Yes}}[/tex]

A guitar string 63.6 cm long vibrates with a standing wave that has five antinodes. Which harmonic is this

Answers

Answer:

fifth harmonic

Explanation:

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