1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Juli2301 [7.4K]
2 years ago
7

Work is NOT done by a person when she?

Physics
1 answer:
garik1379 [7]2 years ago
5 0

Answer:

I think it is pulling the sled off the ice covered back yard.

You might be interested in
The mass of the uniform cantilever is 1100 kg. Determine the force on the beam at A. Determine the force on the beam at B. Use C
Mashcka [7]

Answer:

Force A=-−2,697.75 N

Force B=13, 488.75 N

Explanation:

Taking moments at point A, the sum of clockwise and anticlockwise moments equal to zero.

25 mg-20Fb=0

25*1100g=20Fb

Fb=25*1100g/20=1375g

Taking g as 9.81 then Fb=1375*9.81=13,488.75 N

The sum of upward and downward forces are same hence Fa=1100g-1375g=-275g

-275*9.81=−2,697.75. Therefore, force A pulls downwards

Note that the centre of gravity is taken to be half the whole length hence half of 50 is 25 m because center of gravity is always at the middle

8 0
3 years ago
Nature selects organisms with specific ______to survive and reproduce
Effectus [21]

Answer:

Nature selects organisms with specific heritable traits to survive and reproduce

Explanation:

The Evolution Theory by natural selection dictates that organisms with specific inherited characteristics have better survival chances in the new environment.

Inheriting positive traits such as resistance to a certain disease will improve the survival chances of the organism to enable it reproduce and pass that gene to the next generation.

6 0
3 years ago
Read 2 more answers
A baseball hit just above the ground leaves the bat 27 m/s at 45° above the horizontal. A) How far away does the ball strike the
Sedbober [7]

Answer:

A) The ball hits the ground 74.45 m far from the hitting position.

B) Maximum height of the ball = 18.57 m

Explanation:

There are two types of motion in this horizontal and vertical motion.

We have velocity = 27 m/s at 45° above the horizontal

Horizontal velocity = 27cos45 = 19.09 m/s

Vertical velocity = 27sin45 = 19.09 m/s

Time to reach maximum height,

           v = u + at

           0 = 19.09 - 9.81 t

            t = 1.95 s

So total time of flight = 2 x 1.95 = 3.90 s

A) So the ball travels at 19.09 m/s for 3.90 seconds.

     Horizontal distance traveled = 19.09 x 3.90 = 74.45 m

     So the ball hits the ground 74.45 m far from the hitting position.

B) We have vertical displacement

              S = ut + 0.5 at²

              H = 19.09 x 1.95 - 0.5 x 9.81 x 1.95² = 18.57 m

    Maximum height of the ball = 18.57 m

6 0
3 years ago
A fox with a thick fur would have a survival advantage over other foxes if
Nat2105 [25]
This question is poorly stated, but I assume you mean what conditions are needed. It would have to be cold outside, correct?
8 0
3 years ago
A satellite that goes around the earth once every 24 hours (86,400 s) is called a geosynchronous satellite. If a geosynchronous
Olegator [25]

Answer:

42244138.951 m

Explanation:

G = Gravitational constant = 6.667 × 10⁻¹¹ m³/kgs²

r = Radius of orbit from center of earth

M = Mass of Earth = 5.98 × 10²⁴ kg

m = Mass of Satellite

The satellite revolves around the Earth at a constant speed

Speed = Distance / Time

The distance is the perimeter of the orbit

v=\frac{2\pi \times r}{24\times 3600}

The Centripetal force of the satellite is balanced by the universal gravitational force

m\frac{v^2}{r}=\frac{GMm}{r^2}\\\Rightarrow \frac{\left(\frac{2\pi \times r}{24\times 3600}\right)^2}{r}=\frac{6.667\times 10^{-11}\times 5.98\times 10^{24}}{r^2}\\\Rightarrow \left(\frac{2\pi \times r}{24\times 3600}\right)^2=6.667\times 10^{-11}\times 5.98\times 10^{24}\\\Rightarrow r^3=\frac{6.667\times 10^{-11}\times 5.98\times 10^{24}\times (24\times 3600)^2}{(2\pi)^2}\\\Rightarrow r=\left(\frac{6.667\times 10^{-11}\times 5.98\times 10^{24}\times (24\times 3600)^2}{(2\pi)^2}\right)^{\frac{1}{3}}\\\Rightarrow r=42244138.951\ m

The radius as measured from the center of the Earth) of the orbit of a geosynchronous satellite that circles the earth is 42244138.951 m

6 0
3 years ago
Other questions:
  • You may remember getting toys for Christmas or your birthdays that your parents had to assemble. One such toy requires the use o
    8·1 answer
  • Explain why liquids solidify when they are cooled.
    7·2 answers
  • An actor who memorizes his lines word-for-word has demonstrated _____ learning.
    15·2 answers
  • (quick help please??)A mechanic uses a mechanical lift to raise a car. The car weighs 10,200 N. The work required to do this was
    14·1 answer
  • The earth exerts a force of 1900 N on an or-
    6·1 answer
  • What are the results of habitat loss? choose the most likely outcome
    15·2 answers
  • Under which of the following conditions is the magnitude of the average velocity of a particle moving in one dimension smaller t
    7·1 answer
  • An expansion valve does work on 100 g of water. The system is isolated, and all of the work is used to convert the 90°C water in
    9·1 answer
  • Describe What is the shape of a velocity time graph for an object with constant acceleration
    5·1 answer
  • A 9-volt battery is used to power two lightbulbs in a series circuit. The first light bulb has a
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!