In order to prevent injury in a car crash, it is recommended that you _______. Increase the initial velocity of the collision.

To balance a chemical equation we use______. -coefficients -subscripts

Vitek1552 [10]

Answer:

Coefficients

Explanation:

Coefficients are used to balance chemical equations.
According to the law of conservation of mass, the mass of the reactants in a chemical equation should be equivalent to the mass of the products.
The conservation of mass is achieved in chemical equations is achieved through balancing chemical equations.
Balancing chemical equations is a try and error of putting appropriate coefficients to the reactants or products to ensure that the number of atoms of each element are equal on the side of the reactants and that of products.

3 0

3 years ago

Nresistors, each having resistance equal to 1 2, are arranged in a circuit first in series and then in parallel. What is the rat

aleksandr82 [10.1K]

Answer:

option (b)

Explanation:

Let the resistance of each resistor is R.

In series combination,

The effective resistance is Rs.

rs = r + R + R + .... + n times = NR

Let V be the source of potential difference.

Power in series

Ps = v^2 / Rs = V^2 / NR ..... (1)

In parallel combination

the effective resistance is Rp

1 / Rp = 1 / R + 1 / R + .... + N times

1 / Rp = N / R

Rp = R / N

Power is parallel

Rp = v^2 / Rp = N V^2 / R ..... (2)

Divide equation (1) by equation (2) we get

Ps / Pp = 1 / N^2

5 0

3 years ago

Why are unit of length mass and time independent with each other?

mariarad [96]

Масса (килограмм), длина (метр) и время (секунда) - это 3 из 7 основных единиц в системе СИ.

Базовые единицы произвольно определены как то, что они есть, поэтому они не могут быть получены.

Все другие единицы в системе СИ являются производными от 7 основных единиц, таких как скорость (метр / секунда).

Остальные 4 - это температура (Кельвин), количество вещества (моль), электрический ток (ампер) и светимость (кандела).

4 0

3 years ago

a 360 mile trip began on a greeway in a car traveling at 62 mph. Once the road became a 2 lane highway, the car slowed to 54 mph

Daniel [21]

Answer:

Time spent on the greenway road = 4.5 hours

Time spent on the 2 lane road = 1.5 hours

Explanation:

The distance of the trip is 360 miles and the initial speed of the car is 62 miles/hr and after the road became 2 lane highway the car slowed to 54 miles/hr.

Let us divide the trip into two

Greenway

speed = distance/time

speed = 62 mph

time = a

distance = speed × time

distance = 62a

2 lane highway

speed = distance/time

speed = 54 mph

time = b

distance = speed × time

distance = 54b

Total distance

62a + 54b = 360......................(i)

Total time

a + b = 6..............................(ii)

a = 6-b

insert a in equation (i)

62(6-b) + 54b = 360

372 - 62b + 54b = 360

-8b = 360-372

-8b = - 12

b = 12/8

b = 1.5

from equation (ii)

a + 1.5 = 6

a = 6 - 1.5

a = 4.5

8 0

3 years ago

A Pitot-static tube is mounted on a 2.5 cm pipe where oil (???? = 860 kg/m3, ???? = 0.0103 kg/m·s) is flowing. The Pitot tube is

emmasim [6.3K]

Answer:

$\dot{V}=0.0733 \,m^3.s^{-1}$

Explanation:

Given:

density, $\rho=860\,kg.m^{-3}$

diameter of the pipe, $d=2.5\times 10^{-2}m$

pressure difference, $\Delta P=95.8\times 10^{5}\,Pa$

In case of pitot tube, the velocity is given by:

$v=\sqrt{\frac{2.\Delta P}{\rho} }$

$v=\sqrt{\frac{2\times 95.8\times 10^{5}}{860} }$

$v=149.26\,m.s^{-1}$

Now we know that volumetric flow rate is given as:

$\dot{V}=a.v$

where :

a= cross sectional area of the pipe

v= velocity of flow

$\dot{V}=(\pi\times \frac{(2.5\times 10^{-2})^2}{4} ) \times 149.26$

$\dot{V}=0.0733 \,m^3.s^{-1}$

4 0

3 years ago