Ask question

Ask question

All categories

3 years ago

10

Runner A is initially 6.0 km west of a flagpole and is running with a constant velocity of 9.0 km/h due east. Runner B is initia

lly 5.0 km east of the flagpole and is running with a constant velocity of 8.0 km/h due west. What will be the distance of the two runners from the flagpole when their paths cross? (It is not necessary to convert your answer from kilometers to meters for this problem. You may leave it in kilometers.)

1 answer:

sergejj [24]3 years ago

5 0

Answer:

0.176m from the flagpole, westward.

Explanation:

Let the Eastward be the positive direction. So initially runner A is at position -6km, running with velocity of 9km/h while runner B is at position 5km running at a velocity of -8km/h. We can conduct the following equation for their distances over the same time t

$s_A = -6 + 9t$

$s_B = 5 - 8t$

When A an B meets, they are at the same position and at the same time. So

$s_A = s_B$

$-6 +9t = 5 - 8t$

$17t = 5 + 6 = 11$

$t = 11/17 = 0.647 s$

$s_A = -6 + 9*0.647 = -0.176 m$

So where they meet is 0.176m from the flagpole, westward.

You might be interested in

A tray is moved horizontally back and forth in simple harmonic motion at a frequency of f = 2.07 Hz. On this tray is an empty cu

Anettt [7]

Answer:

Explanation:

Given

Frequency of SHM is $f=2.07\ Hz$

Amplitude of SHM is $A=3.13\ cm$

Cup begins to slip when it overcomes the friction force

Friction force $F_s=\mu mg$

Applied force $F=ma$

$ma=\mu mg$

$a=\mu g$

and maximum acceleration during SHM is

$a=A\omega ^2$

$a=A(2\pi f)^2$

$a=3.13\times 10^{-2}\times (2\pi 2.07)^2$

$a=5.296\ m/s^2$

$\mu =\frac{a}{g}$

$\mu =\frac{5.296}{9.8}=0.54$

6 0

4 years ago

Read 2 more answers

A 1900kg car starts from rest and drives around a flat 65-m-diameter circular track. The forward force provided by the car's dri

s344n2d4d5 [400]

Answer:

$The\quad magnitude\quad of\quad the\quad car's\quad acceleration\quad at\quad t=13s\quad \quad =2.52m/{ s }^{ 2 }\\ The\quad direction\quad of\quad the\quad car's\quad acceleration\quad at\quad t=13s\quad =15.{ 72 }^{\o}\\The\quad car\quad begins\quad to\quad slide\quad out\quad \quad of\quad the\quad circle\quad after\quad 26.09s.\quad \quad \quad \quad$

Explanation:

8 0

3 years ago

It was a children versus grown-ups competition at school. One event required the adult to throw a basketball as far as he could.

aleksklad [387]

Based on Newton's Law, the event is not fair because:

<span>No, because a basketball is bigger than a baseball, and objects that are bigger accelerate slower.

I hope my answer has come to your help. God bless and have a nice day ahead!</span>

4 0

3 years ago

Read 2 more answers

True or False? Materials that are good conductors of heat are usually poor conductors of electricity.

alexandr402 [8]

False

HOPE THIS WILL HELP YOU

5 0

3 years ago

Read 2 more answers

Stars form from clouds of gas and dust. As a protostar gravitationally contracts within its parent cloud, "conservation of angul

vredina [299]

Answer:

D) True. the protostar rotates more quickly.

Explanation:

If the system is isolated, the angular momentum must be retained.

Initial

L₀ = I w₀

Final

$L_{f}$ = $I_{f}$ $w_{f}$

L₀ = $L_{f}$

I w₀ = $I_{f}$ $w_{f}$

$w_{f}$ = I / $I_{f}$ w₀

In general, the radius of the cloud decreases significantly to form the star, the moment of inertia must decrease, so the angular velocity must increase

Let's examine the answers

A) False. The opposite happens

B) False. Speed changes

C) False. For this there must be an external force, which does not exist

D) True. You agree with the above

5 0

3 years ago