In the elements square on the periodic table, the number with the greatest numerical value the

Unlike mechanical waves such as sound or earthquake waves, EM waves can travel through empty space. True or false

Alex777 [14]

Answer:

its true

Explanation:

5 0

3 years ago

How long does it take a car traveling at 50 mph to travel 75 miles? Use one of the following to find the answer.

yanalaym [24]

Answer:

90 Minutes

Explanation:

t = d / v

t = 75 / 50

t = 1.5 hour

t = 90 minutes.

8 0

2 years ago

In which situation would an object weigh the LEAST? (assume all the objects have the same mass)

inessss [21]

Answer:

An object on the moon would weigh the LEAST among these. So correct answer is B.

Explanation:

Weight of an object on any place is given by:

W = Mass * Acceleration due to gravity(g)

It means when masses of different objects those are in different places are same, the weight of those objects depends upon the 'g' of that particular place.

As we know, acceleration due to gravity on surface of moon (g') is 6 times weaker than the acceleration on surface of earth (g), which is due to the large M/R^2 of the earth than the moon.

i.e. g' = g/6 so W' = W/6

And in the space between the two, the object is weightless.

8 0

3 years ago

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Who invented the assembly line what purpose does it serve

insens350 [35]

Answer:

Ransom E. Olds was the person who invented assembly line.

The assembly line method was the very first method to be used in automotive sector and was the prototype for which Henry Ford industries had developed his own.

Explanation:

Ransom E. Olds was the person who invented assembly line.

The assembly line method was the very first method to be used in automotive sector and was the prototype for which Henry Ford industries had developed his own. Henry Ford enhanced the design of assembly line through the use of a conveyor system's running platforms.

The assembly line has always been recognized as among the 20th century's greatest inventions. It so profoundly influenced the industrialized world that industries that didn't adopt the trend quickly became extinct and was one of the primary factors that helped to incorporate the automobile into American society.

6 0

3 years ago

A metal block of mass 3 kg is falling downward and has velocity of 0.44 m/s when it is 0.8 m above the floor. It strikes the top

Anton [14]

Answer:

$y_{max} = 0.829\,m$

Explanation:

Let assume that one end of the spring is attached to the ground. The speed of the metal block when hits the relaxed vertical spring is:

$v = \sqrt{(0.8\,\frac{m}{s})^{2} + 2\cdot (9.807\,\frac{m}{s^{2}} )\cdot (0.4\,m)}$

$v = 2.913\,\frac{m}{s}$

The maximum compression of the spring is calculated by using the Principle of Energy Conservation:

$(3\,kg)\cdot (9.807\,\frac{m}{s^{2}})\cdot (0.4\,m) + \frac{1}{2}\cdot (3\,kg)\cdot (2.913\,\frac{m}{s} )^{2} = (3\,kg) \cdot (9.807\,\frac{m}{s^{2}})\cdot (0.4\,m-\Delta s) + \frac{1}{2}\cdot (2000\,\frac{N}{m})\cdot (\Delta s) ^{2}$

After some algebraic handling, a second-order polynomial is formed:

$12.728\,J = \frac{1}{2}\cdot (2000\,\frac{N}{m} )\cdot (\Delta s)^{2} - (3\,kg)\cdot (9.807\,\frac{m}{s^{2}} )\cdot \Delta s$

$1000\cdot (\Delta s)^{2}-29.421\cdot \Delta s - 12.728 = 0$

The roots of the polynomial are, respectively:

$\Delta s_{1} \approx 0.128\,m$

$\Delta s_{2} \approx -0.099\,m$

The first root is the only solution that is physically reasonable. Then, the elongation of the spring is:

$\Delta s \approx 0.128\,m$

The maximum height that the block reaches after rebound is:

$(3\,kg) \cdot (9.807\,\frac{m}{s^{2}} )\cdot (0.4\,m-\Delta s) + \frac{1}{2}\cdot (2000\,\frac{N}{m})\cdot (\Delta s)^{2} = (3\,kg)\cdot (9.807\,\frac{m}{s^{2}} )\cdot y_{max}$

$y_{max} = 0.829\,m$

4 0

3 years ago

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