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3 years ago

1) Calculate the speed of a runner who runs 100 m in 20s

1 answer:

5 0

This is how you calculate his speed, for the 100metres. That is, the average speed for the entire distance, including the start from intertia until the race end where the athlete is decelerating. Multiply the time by 10, and divide 3600 by that figure. i.e. 10 by10 equals 100. Divide 3600 by 100 and you get 36 which is the speed figure you requested.

A female athlete ran 200 metres a few years ago and in the middle section of the race covered 100 metres in that race in a time under 10 seconds. That is, she ran a sub 10second 100metres from a flying start. This great athlete from Slovenia, also ran a 100 metre race (from a stationary start) in a time under 11 seconds, when she was 48 years of age. Her name is Merlene Ottey.

You might be interested in

Which two statements about composite materials are true?

Lostsunrise [7]

Answer:

Here down below is 3 things true about composite materials

Explanation:

-They’re made up of more than one substance.

-They have the same or similar properties as the materials used to make them.

-They’re always made of metal.

-They’re readily available in nature.

4 0

3 years ago

a van moves with a constant speed of 79 km/h how long will it take to travel a distance of 502 kilometers

Mazyrski [523]

Answer:

6.35hours

Explanation:

s=vt

t=s/v=502/79=6.35hours

5 0

3 years ago

Question 5 At 12:00 pm, a spaceship is at position ⎡⎣324⎤⎦ km ⎣ ⎢ ⎡ 3 2 4 ⎦ ⎥ ⎤ km away from the origin with respect to so

Anettt [7]

Answer:

[1, 6, -2]

Explanation:

Given the following :

Initial Position of spaceship : [3 2 4] km

Velocity of spaceship : [-1 2 - 3] km/hr

Location of ship after two hours have passed :

Distance moved by spaceship :

Velocity × time

[-1 2 -3] × 2 = [-2 4 -6]

Location of ship after two hours :

Initial position + distance moved

[3 2 4] + [-2 4 -6] = [3 + (-2)], [2 + 4], [4 + (-6)]

= [3-2, 2+4, 4-6] = [1, 6, -2]

4 0

3 years ago

It has been suggested, and not facetiously, that life might have originated on Mars and been carried to Earth when a meteor hit

damaskus [11]

Answer:

$a=3125000 m/s^2\\a=3.125*10^6 m/s^2$

Acceleration, in m/s, of such a rock fragment = $3.125*10^6m/s^2$

Explanation:

According to Newton's Third Equation of motion

$V_f^2-V_i^2=2as$

Where:

$V_f$ is the final velocity

$V_i$ is the initial velocity

a is the acceleration

s is the distance

In our case:

$V_f=V_{escape}, V_i=0,s=4 m$

So Equation will become:

$V_{escape}^2-V_i^2=2as\\V_{escape}^2-0=2as\\V_{escape}^2=2as\\a=\frac{V_{escape}^2}{2s}\\a=\frac{(5*10^3m)^2}{2*4}\\a=3125000 m/s^2\\a=3.125*10^6 m/s^2$

Acceleration, in m/s, of such a rock fragment = $3.125*10^6m/s^2$

5 0

3 years ago

1) how does reflection differ from diffraction?

Evgesh-ka [11]

Answer: (1) The correct answer is A.

(2) The correct answer is D.

Explanation:

(1)

Reflection is the sending back of light from the surface without absorbing it. In the reflection phenomenon, the wave does not continue moving forward.

Diffraction is the bending of the light around the obstacle. In the diffraction phenomenon, the wave travels forward after striking around the obstacle.

Therefore, the correct answer is A.

(2)

Amplitude is the maximum displacement in the medium from the rest position.

The amount of energy is related to the amplitude. Amplitude is related to the amount of energy carried by the wave. Low energy wave is characterized by a low amplitude. High energy wave is characterized by a high amplitude.

Therefore, the correct option is D.

5 0

3 years ago

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