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Genrish500 [490]
3 years ago
7

A suspicious-looking man runs as fast as he can along a moving sidewalk from one end to the other, taking 2.50 s. Then security

agents appear, and the man runs as fast as he can back along the sidewalk to his starting point, taking 13.0 s. What is the ratio of the man's running speed to the sidewalk's speed?
Physics
2 answers:
Zigmanuir [339]3 years ago
6 0
13:9 because he starts back then runs slower
snow_tiger [21]3 years ago
6 0

Answer:

The ratio of the man's running speed to the sidewalk's speed: 5: 26.

Explanation:

Let the distance between the sidewalk from one end to the other be x

Distance covered by the man = x

Time taken by the person to cover x distance = 2.50 seconds

Speed of the man while running to other end point = S

S=\frac{x}{2.50 s}..[1]

Distance covered by the man by running back to his starting point after agents appears = x

Time taken by the person to cover x distance after agents appears = 13.0 seconds

Speed of the man while running back to starting point after agents appears = S'

S'=\frac{x}{13.0 s}...[2]

The ratio of the man's running speed to the sidewalk's speed:

[2] ÷ [1]

\frac{S'}{S}=\frac{\frac{x}{13.0 s}}{\frac{x}{2.50 s}}=\frac{5}{26}

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kaheart [24]

Answer:

B) t = 1.83 [s]

A) y = 16.51 [m]

Explanation:

To solve this problem we must use the following equation of kinematics.

v_{f} =v_{o} -g*t

where:

Vf = final velocity = 0

Vo = initial velocity = 18 [m/s]

g = gravity acceleration = 9.81 [m/s²]

t = time [s]

Note: the negative sign in the above equation means that the acceleration of gravity is acting in the opposite direction to the motion.

A) The maximum height is reached when the final velocity of the ball is zero.

0 = 18 - (9.81*t)

9.81*t = 18

t = 18/9.81

t = 1.83 [s], we found the answer for B.

Now using the following equation.

y = y_{o} + v_{o}*t - 0.5*g*t^{2}\\

where:

y = elevation [m]

Yo = initial elevation = 0

y = 18*(1.83) - 0.5*9.81*(1.83)²

y = 16.51 [m]

7 0
2 years ago
A satellite is in a circular orbit around an unknown planet. The satellite has a speed of 1.75 104 m/s, and the radius of the or
Arisa [49]

Answer:

v = 1.32 10² m

Explanation:

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Let's calculate the mass of the planet

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With this die we clear the equation to find the orbit of the second satellite

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8 0
3 years ago
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kotykmax [81]

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Explanation:

3 0
3 years ago
Consider the image above. Vi = the initial velocity and Vf = the final velocity. Is there acceleration? Explain your answer.
lutik1710 [3]
<span><span>Velocity is a vector, and the initial and final ones are in opposite directions.
There must have been acceleration in order to change the direction of motion.</span>

A) No. The initial and final velocities are the same.
This is all wrong, and not the correct choice.
It's "Yes", and the initial and final velocities are NOT the same.

B) Yes. The ball had to slow down in order to change direction.
This is poor, and not the correct choice.
The "Yes" is correct, but the explanation is bad.
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This is all wrong, and not the correct choice.
It's "Yes", there IS acceleration, and the ball's velocity is NOT constant.

D) Yes. Even though the initial and final velocities are the same, there is a change in direction for the ball.
This choice is misleading too.
The "Yes" is correct ... there IS acceleration.
The change in direction is the reason.
The initial and final velocities are NOT the same.  Only the speeds are.
</span>
3 0
3 years ago
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choli [55]

F = 52000 N

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6 0
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