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3 years ago

What is the speed of a runner that runs 400m in 48.42 seconds?

Physics

1 answer:

nika2105 [10]3 years ago

3 0

Answer:

The speed is that it would take 121.05 seconds to run a kilometer.

Explanation:

Since there are 1000 meters in a kilometer, divide 400 meters by 4, and 48.42 by 4. Then you get 100 meters equals 12.105 seconds. Multiply that by ten, and you get 121.05 seconds

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What are the two most important traits between a whale and a shark?

nordsb [41]

Answer:

Both are aquatic animals and are hunters

Explanation:

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3 years ago

When is the magnitude of the acceleration of a mass on a spring at its maximum value?

Andreas93 [3]

Answer:

A. when the mass has a speed of zero

Explanation:

In mass-spring system, the velocity and the acceleration are in anti-phase, which means that when one of the two quantities is maximum, the other one is zero, and vice-versa.

In fact:

- When the displacement of the spring is zero (x=0), the velocity is maximum, due to conservation of energy. In fact, as the displacement is zero, the elastic potential energy of the system (given by $\frac{1}{2}kx^2$ ) is zero, therefore the kinetic energy (given by $\frac{1}{2}mv^2$ ) must be maximum, and so the velocity (v) is also maximum. On the cotnrary, acceleration (a) is directly proportional to the restoring force of the spring, given by

$F=-kx$

so we see that when x=0, then the force is zero: F=0, and so the acceleration is zero as well.

- When the displacement of the spring is maximum, the velocity is zero, due to conservation of energy. In fact, as the displacement is maximum, the elastic potential energy of the system (given by $\frac{1}{2}kx^2$ ) is maximum, therefore the kinetic energy (given by $\frac{1}{2}mv^2$ ) must be zero, and so the velocity (v) is also zero. On the cotnrary, since acceleration (a) is directly proportional to the restoring force of the spring, given by

$F=-kx$

so we see that when x=maximum, then the force is maximum, and so the acceleration is maximum as well.

Based on this, the correct answer is

A. when the mass has a speed of zero

5 0

3 years ago

Read 2 more answers

What type of friction is using chalk in the summer to draw on the ground in Copley square?

Lera25 [3.4K]

The second option rolling friction

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3 years ago

I'm writing a story about Granny using old-fashioned laundry bluing to freshen dingy yellow clothes. I would like to explain WHY

Katena32 [7]

By combining blue with yellow light is like combining blue light with red and green light. The result of combining these three primary colors of light is to produce white light.

<h3>What is laundry bluing ?</h3>

Laundry bluing is a product adds a trace amount of blue dye to white fabric during laundering to improve its appearance.

Bluing products in higher concentrations can darken jeans and other blue cloth.

The blue overpowered the yellow to reflect white (at least the appearance of white to the human eye).

Blue and yellow are complementary colors that combine to reflect white, Fabrics.

Here,

Yellow light is a combination of red and green light. So combining blue with yellow light is like combining blue light with red and green light. The result of combining these three primary colors of light is to produce white light.

Learn more about White light here:brainly.com/question/16317768

#SPJ1

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2 years ago

You are driving your car along a country road at a speed of 27.0 m/s. as you come over the crest of a hill, you notice a farm tr

Bezzdna [24]

speed of the car = 27 m/s

speed of truck ahead = 10 m/s

relative speed of car with respect to truck

$v_r = 27 - 10 = 17 m/s$