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Goshia [24]
3 years ago
5

Martha must carry a 45 N package up three flights of stairs. Each flight of stairs has a height of 2.3m, and the actual distance

of a diagonal path she walks up the stairs is 10 m. What is the total work done on the package?
Physics
1 answer:
Darina [25.2K]3 years ago
3 0

Answer:

310.5 J

Explanation:

The total work done by Martha is equal to the increase in gravitational potential energy of the package, which is equal to

\Delta U = mg\Delta h

where

(mg) = 45 N is the weight of the package

\Delta h is the increase in height of the package

The package is carried up 3 flights of stairs, each one with a height of 2.3 m, so the total increase in heigth is

\Delta h = 3 \cdot 2.3 m=6.9 m

And so, the work done by Martha is

U=(45 N)(6.9 m)=310.5 J

You might be interested in
A horizontal 810-N merry-go-round of radius 1.60 m is started from rest by a constant horizontal force of 55 N applied tangentia
Sloan [31]

Answer:

576 joules

Explanation:

From the question we are given the following:

weight = 810 N

radius (r) = 1.6 m

horizontal force (F) = 55 N

time (t) = 4 s

acceleration due to gravity (g) = 9.8 m/s^{2}

K.E = 0.5 x MI x ω^{2}

where MI is the moment of inertia and ω is the angular velocity

MI = 0.5 x m x r^2

mass = weight ÷ g = 810 ÷ 9.8 = 82.65 kg

MI = 0.5 x 82.65 x 1.6^{2}

MI = 105.8 kg.m^{2}

angular velocity (ω) = a x t

angular acceleration (a) = torque ÷ MI

where torque = F x r = 55 x 1.6 = 88 N.m

a= 88 ÷ 105.8 = 0.83 rad /s^{2}

therefore

angular velocity (ω) = a x t = 0.83 x 4 = 3.33 rad/s

K.E = 0.5 x MI x ω^{2}

K.E = 0.5 x 105.8 x 3.33^{2} = 576 joules

6 0
3 years ago
What can always be said about a negatively-charged ion?
KiRa [710]

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

5 0
3 years ago
A circus act involves a trapeze artist and a baby elephant. They are going to balance on a teeter-totter that is 10 meters long
elena-s [515]

Answer:

Explanation:

Balance point will be achieved as soon as the weight of the baby elephant creates torque equal to torque created by weight of woman about the pivot. torque by weight of woman

weight x distance from pivot

= 500x 5

= 2500 Nm

torque by weight of baby woman , d be distance of baby elephant from pivot at the time of balance

= 2500x d

for equilibrium

2500 d = 2500

d = 1 m

So elephant will have to walk up to 1 m close to pivot or middle point.

6 0
3 years ago
Volume can be measured in: <br>A. cubic centimeters. <br>B. centimeters. <br>C. square centimeters.
Ad libitum [116K]

Answer-

A. cubic centimeters.

Hope this helps!

8 0
3 years ago
Read 2 more answers
Please help me
melamori03 [73]
<h2>Question:</h2>

An automobile is driving uphill. Which form of energy is not involved in this process?

<h2>Choosing:</h2>

electromagnetic

potential

kinetic

chemical

<h2>Answer:</h2>

<u>Electromagnetic</u><u> </u>

<h3><u>#READINGHELPSWITHLEARNING</u><u> </u></h3><h3><u>#CARRYONLEARNING</u><u> </u></h3><h3><u>#STUDYWELL</u><u> </u></h3>
7 0
3 years ago
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