Which of the following equations correctly models a balanced single replacement reaction?

On a spacecraft, two engines are turned on for 684 s at a moment when the velocity of the craft has x and y components of v0x 43

Natasha2012 [34]

As we know by the kinematics

$\delta x = v_x * t + \frac{1}{2} at^2$

$4.11106 = 4370* 684 + \frac{1}{2}a_x*684^2$

$4.11106 = 2989080 + 233928*a_x$

$a_x = -12.78 m/s^2$

Similarly for Y direction

$\delta y = v_y * t + \frac{1}{2} at^2$

$6.07106 = 6280* 684 + \frac{1}{2}a_y*684^2$

$6.07106 = 4295520 + 233928*a_y$

$a_y = -18.36 m/s^2$

8 0

3 years ago

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21. True or False: Static friction prevents you from slipping when you walk on a sidewalk.

Sloan [31]

Answer:

Yes it is true because static friction help us to make grip between the foot and the ground surface

Explanation:

Yes, as we know that the friction between two surface is of two types

1) Static friction

2) Kinetic friction

When two surface moves relative to each other then the friction force between two surface is kinetic friction and it always opposes the relative motion of two rough surface

While when one surface has tendency to move with respect to its contact surface but if it can not move on it then in this case it is static friction

So relative motion is not possible in this type of friction

So static friction helps to prevent slipping

3 0

4 years ago

You are called to the crime scene immediately and you begin your investigation at 2 PM. The first thing you do is take the tempe

adell [148]

As per Newton's law of cooling we know that

$\frac{\Delta T}{dt} = k(T_avg - T_s)$

in 5 hours the body temperature becomes 79.6 from 84.4

while the surrounding temperature is given as 68 degree F

now from above formula

$\frac{84.4 - 79.6}{5} = k (\frac{84.4 + 79.6}{2} - 68)$

$0.96 = k(14)$

now let say the person died "t" time ago

now we will have

$\frac{98.6 - 84.4}{t} = k (\frac{98.6 + 84.4}{2} - 68)$

$\frac{14.2}{t} = k(23.5)$

$\frac{14.2}{t} = \frac{0.96}{14}(23.5)$

$t = 8.8 hours = 9hours (approx)$

so he died at approx 5 Am in morning

5 0

3 years ago

What type of essay explains the results of a specific event?

madreJ [45]

Answer:

a

Explanation:

6 0

3 years ago

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Jon recently drove to visit his parents who live 648 miles away. On his way there his average speed was 14 miles per hour faster

Vladimir79 [104]

Answer:

speed of the Jon visiting parents = 56 mph

speed of the Jon when returning from home = 56 - 14 = 42 mph

Explanation:

given,

distance of Jon parent's house = 648 mile

avg speed when he was visiting his parent's house be 'x' mph

avg speed when he is returning from his parent's house be 'x-14' mph

total time taken = 27 hours

total distance = speed × time

648 = x × t₁

$t_1 = \dfrac{648}{x}$

648 = ( x - 14 ) × t₂

$t_2 = \dfrac{648}{x-14}$

t = t₁ + t₂

$27 = \dfrac{648}{x} + \dfrac{648}{x-14}$

$1 = 24 (\dfrac{1}{x} + \dfrac{1}{x-14})$

x² - 62 x + 336 = 0

x² - 56 x - 6 x + 336 = 0

(x - 56 )(x - 6)=0

on solving

x = 56 ,6

hence, speed of the Jon visiting parents = 56 mph

speed of the Jon when returning from home = 56 - 14 = 42 mph

8 0

3 years ago

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