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3 years ago

A 95.0kg weightlifter pushes on a 800,000 kg wall for 400s but it does not move. How much work does he do on the wall?

1 answer:

7 0

<span>The weightlifter does no work. Although he has exerted force, work is the product of force over distance. Since he has not moved the wall he has done no work.</span>

You might be interested in

Which statement describes the magnetic field inside a bar magnet?

kakasveta [241]

The statement that describes the magnetic field inside a bar magnet is as follows: it points from north to south.

<h3>What is a bar magnet?</h3>

A bar magnet is a permanent magnet of rectangular shape.

A magnet generally possess a magnetic field, which is a condition in the space around a magnet which there is a detectable magnetic force and the presence of two magnetic poles.

A bar magnet like every other magnet possesses a magnetic field that points from the north pole to the south pole.

Learn more about magnets at: brainly.com/question/13026686

#SPJ1

5 0

1 year ago

emperature is most closely related to which property of a liquid? (1 point) Select one: a. the volume of the liquid b. the numbe

Rainbow [258]

Answer

b. the number of atoms in each molecule.

Explanation:

5 0

3 years ago

viva [34]

An LDR's resistance changes with light intensity, while a thermistor's resistancce changes with temperature.

In dark, LDR's resistance is large and in the day/light LDR's resistance is small.

At low temperature, thermistor's resistance is large, while at large temperature it resistance is small.

In an LDR Resistance increases as light intensity falls, while in a thermistor resistance falls as temperature falls.

5 0

2 years ago

True.or false A railroad track runs southwest to northeast.

telo118 [61]

Answer:

ns for high-speed rail in the United States date back to the High Speed Ground Transportation Act of 1965. Various state and federal proposals have followed. Despite being one of the world's first countries to get high-speed trains (the Metroliner service in 1969), it failed to spread. Definitions of what constitutes high-speed rail vary, including a range of speeds over 110 mph (180 km/h) and dedicated rail lines. Inter-city railwith top speeds between 90 and 125 mph (140 and 200 km/h) is sometimes referred to in the United States as higher-speed rail.[1]

Amtrak's Acela Express (reaching 150 mph, 240 km/h), Silver Star, Northeast Regional, Keystone Service, Vermonter and certain MARC Penn Line express trains (all five reaching 125 mph, 201 km/h) are the only high-speed services in the country.

As of 2020, the California High-Speed Rail Authority is working on the California High-Speed Rail project and construction is under way on sections traversing the Central Valley. The Central Valley section is planned to open in 2029 and Phase I is planned for completion in 2031.[2]

Contents

1 Definitions in American context

2 History

2.1 Faster inter-city trains: 1920–1941

2.2 Post-war period: 1945–1960

2.3 First attempts: 1960–1992

2.4 Renewed interest: 1993–2008

2.5 Plans for 2008–2013

3 Current state and regional efforts

3.1 The Northeast

3.1.1 Northeast Corridor: Next Generation High-Speed Rail

3.1.1.1 Proposed routes

3.1.2 Northeast Maglev proposal

3.1.3 New Jersey–New York City upgrades

3.1.4 New York

3.1.5 Pennsylvania

3.2 Western States

3.2.1 California

3.2.2 Pacific Northwest

3.2.3 Arizona

3.3 Mid-Atlantic and the South

3.3.1 Florida

3.3.2 Southeast

3.3.3 Texas

3.4 Midwest

3.4.1 Illinois and the Midwest

3.5 The Southwest

4 Federal high-speed rail initiatives

4.1 American Recovery and Reinvestment Act of 2009

4.1.1 Strategic plan

4.2 2009 federal grant funding

4.3 2010 allocation

4.3.1 Cancellation of funds for Wisconsin, Ohio, and Florida

4.4 2011 and 2012 proposals and rejections of funding

5 See also

6 Notes

7 Further reading

8 External links

Explanation:

3 0

2 years ago

For a block to move down an inclined plane what force has to be the greatest?

Hatshy [7]

Answer:

D) True. This is what creates the body weight

Explanation:

Let's write Newton's second law for this case. For inclined planes the reference system takes one axis parallel to the plane (x axis) and the other perpendicular to the plane (y axis)

X axis

Wx -fr = ma

Y Axis

N - Wy = 0

With trigonometry we can find the components of weight

sin θ = Wₓ / W

cos θ = $W_{y}$ / W

Wₓ = W sin θ

$W_{y}$ = W cos θ

W sin θ - fr = ma

From this expression as it indicates that the body is descending the force greater is the gravity that create the weight of the body

Let's examine the answers

A False This force does not apply because it is not a spring

B) False. It is balanced at all times with the component (Wy) of the weight

C) False. For there to be a rope, if it exists you should be less than the weight component for the block to lower

D) True. This is what creates the body weight

E) False. The cutting force occurs for force applied at a single point and gravity is applied at all points

5 0

3 years ago