What is the difference in momentum when the masses are equal

When observing a group of children at a daycare center, Emily made the following observations: Five year old children played in

konstantin123 [22]

This question is not about physics science.

The answer is: option <span>a. Five-year-old children have longer attention spans than three-year-old children.

It is the attention ability what let the older children to stay longer in one location instead of being moving between different activities. The younger children who cannot keep their attention long time in a same activity entertain themselves by changing activities.
</span>

5 0

3 years ago

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A rifle fires a bullet into a giant slab of butter on a frictionless surface. The bullet penetrates the butter, but while passin

Vera_Pavlovna [14]

Answer:

V= 3.48 m/s

Explanation:

8 0

3 years ago

A farmer plans to build a rectangular garden in back of his house so that he only needs fencing on 3 sides of the garden. if he

kogti [31]

Answer:

90 feet

Explanation:

The farmer wants the second side of the garden to be 30 feet longer than the back of his house.

If the back of his house=x ft

The second side=(x+30) ft

Note that the farmer does not fence the side on the back of the house.

Area of the garden = 400 square feet

Area of a Rectangle= Length X Width

400 = x(x+30)

$x^2+30x-400=0\\x^2+40x-10x-400=0\\x(x+40)-10(x+40)=0\\(x+40)(x-10)=0\\$

x+40=0 or x-10=0

x=-40 or x=10

Since length cannot be negative, x=10 ft

The Length of the Fencing the farmer will buy will be the perimeter of the three sides.

Perimeter of the three sides = x+(x+30)+(x+30)

=3x+60

=3(10)+60=90 ft

The farmer needs to buy a fencing of length 90 feet.

4 0

4 years ago

What adaptation in frogs enables them to swim

Flauer [41]

Answer:

Most of the frogs have webbed feet which helps them swim. The thin skin between the toes helps them to push through the water. The frog's feet is webbed ,So they can easily swim.. The skin between toes are flexible soo they can freely push and pull it

Explanation:

6 0

4 years ago

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A cylinder of mass mm is free to slide in a vertical tube. The kinetic friction force between the cylinder and the walls of the

Zinaida [17]

Answer:

$y = \frac{-f +/- \sqrt{f^{2} +2kmg}}{k}$

Explanation:

Let y₀ be the initial position of the cylinder when the spring is attached and y its position when it is momentarily at rest.From work-kinetic energy principles, The work done by the spring force + work done by friction + work done by gravity = kinetic energy change of the cylinder

work done by the spring force = ¹/₂k(y₀² - y²)

work done by friction = - f(y - y₀)

work done by gravity = mg(y - y₀)

kinetic energy change of the cylinder = ¹/₂m(v₁² - v₀²)

So ¹/₂k(y₀² - y²) - f(y - y₀) + mg(y - y₀) = ¹/₂m(v₁² - v₀²)

Since the cylinder starts at rest, v₀ = 0. Also, when it is momentarily at rest, v₁ = 0

¹/₂k(y₀² - y²) - f(y - y₀) + mg(y - y₀) = ¹/₂m(0² - 0²)

¹/₂k(y₀² - y²) - f(y - y₀) + mg(y - y₀) = 0

¹/₂ky₀² + fy₀ - mgy₀ -¹/₂ky² - fy + mgy = 0

¹/₂ky₀² + fy₀ - mgy₀ = ¹/₂ky² + fy - mgy

Let y₀ = 0, then the left hand side of the equation equals zero. So,

0 = ¹/₂ky² + fy - mgy

¹/₂ky² + fy - mgy = 0

Using the quadratic formula

$y = \frac{-f +/- \sqrt{f^{2} - 4 X\frac{k}{2} X -mg}}{2 X \frac{k}{2} }\\ y = \frac{-f +/- \sqrt{f^{2} +2kmg}}{k}$

4 0

3 years ago