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zysi [14]
3 years ago
14

A runner runs the first 400m of a race in 80s, the second 400m in 70s and the final 800m in 130s. What was her average speed for

this run?
Physics
1 answer:
-BARSIC- [3]3 years ago
5 0

Answer: The average speed is 5.71 m/s

Explanation:

The average speed in this run will be the quotient between the total distance that the runner traveled, and the total time it took.

Distance = 400m + 400m + 800m = 1600m

Time = 80s + 70s + 130s = 280s

Then the average speed is:

S = 1600m/280s = 5.71 m/s

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A cubical surface surrounds a point charge q . Describe what happens to the total flux through the surface if (c) the surface is
valentina_108 [34]

Answer:

Gauss law states that the electric flux is defined as the electric field multiplied by the area of the surface in a plane perpendicular to the field.

Explanation:

Mathematically,

Φ=Q ϵo

Where;

Q is enclosed charge

ϵo is the permittivity of the free space

According to Gauss law, which states that the electric flux is defined as the electric field multiplied by the area of the surface in a plane perpendicular to the field.

Φ=Q ϵo

Where;

Q is enclosed charge

ϵo is the permittivity of the free space

If the cube is transformed into a sphere the total flux in the electric field remains unchanged or remains the same. This is because the gaussian law does not postulate that electric flux is dependent on the object in a plane. Hence, the transformation of the cube to a sphere does not affect the electric flux generated in the field.

To learn more about how the total flux through a sphere relates to the surface change, click brainly.com/question/4362789

#SPJ4

3 0
1 year ago
Find the work done lifting a 290-pound weight 28 feet in the air.
Nataly [62]
The answer is d.8,120 foot-pounds
6 0
3 years ago
Read 2 more answers
a 0.199 kg snowball moving west makes an inelastic collision with a 2.89 kg box moving 0.523 m/s west. afterward,they move west
kogti [31]

Answer:

The initial velocity of the snowball was 22.21 m/s

Explanation:

Since the collision is inelastic, only momentum is conserved. And since the snowball and the box move together after the collision, they have the same final velocity.

Let m_1 be the mass of the ball, and v_1 be its initial velocity; let m_2 be the mass of the box, and v_2 be its velocity; let v_f be the final velocity after the collision, then according to the law of conservation of momentum:

m_1v_1+m_2v_2=v_f(m_1+m_2).

From this we solve for v_1, the initial velocity of the snowball:

\boxed{v_1=\frac{v_f(m_1+m_2)-m_2v_2}{m_1}}

now we plug in the numerical values m_1=0.199\:kg, m_2=2.89\:kg, v_2=0.523\:m/s, and v_f=1.92\:m/s to get:

v_1=\frac{1.92*(0.199+2.89)-2.89*0.523}{0.199}

\boxed{v_1=22.21\:m/s}

The initial velocity of the snowball is 22.21 m/s.

<em>P.S: we did not take vectors into account because everything is moving in one direction—towards the west.</em>

4 0
2 years ago
Water, H2O, is made up of different elements, hydrogen and oxygen. Is this type of combination a mixture or a pure substance? A)
strojnjashka [21]

the correct answer is D i just got it on USATestPrep. Your welcome.

7 0
2 years ago
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How many leptons are in ⁷₃Li?
shutvik [7]

-- Electrons are leptons.  There are <em>three</em> electrons in each neutral Lithium atom.

The last two parts of the question are absurd.

-- Bonbons are candy, not atomic particles.  A bonbon cannot fit into a Lithium atom.

-- A pentagon is a closed geometric figure that has five sides.  Although you could, in principle, have a pentagon small enough to fit into a Lithium atom, you could never find a piece of paper small enough to draw it on.

5 0
3 years ago
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