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4 years ago

How are parentheses used in chemical formulas

2 answers:

8 0

In a chemical compound, parenthesis are used to distinguish the number of polyatomic ions from the number of atoms. Such as in the compound calcium nitrate, it is written as $Ca(NO_{3} ) _{2}$ . This means there are two nitrate ions for every one calcium ion.<span>
</span>

Zarrin [17]4 years ago

3 0

<span>it is meant to distinguish the number of polyatomic ions from the number of atoms in a given polyatomic ion. an example is Ca(NO3)2</span>

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Consider massive gliders that slide friction-free along a horizontal air track. Glider A has a mass of 1 kg, a speed of 1 m/s, a

mamaluj [8]

Answer:

0.167m/s

Explanation:

According to law of conservation of momentum which States that the sum of momentum of bodies before collision is equal to the sum of the bodies after collision. The bodies move with a common velocity after collision.

Given momentum = Maas × velocity.

Momentum of glider A = 1kg×1m/s

Momentum of glider = 1kgm/s

Momentum of glider B = 5kg × 0m/s

The initial velocity of glider B is zero since it is at rest.

Momentum of glider B = 0kgm/s

Momentum of the bodies after collision = (mA+mB)v where;

mA and mB are the masses of the gliders

v is their common velocity after collision.

Momentum = (1+5)v

Momentum after collision = 6v

According to the law of conservation of momentum;

1kgm/s + 0kgm/s = 6v

1 =6v

V =1/6m/s

Their speed after collision will be 0.167m/s

6 0

3 years ago

A projectile is shot horizontally at 23.4 m/s from the roof of a building 55.0 m tall. (a) Determine the time necessary for the

jeka94

(a) 3.35 s

The time needed for the projectile to reach the ground depends only on the vertical motion of the projectile, which is a uniformly accelerated motion with constant acceleration

a = g = -9.8 m/s^2

towards the ground.

The initial height of the projectile is

h = 55.0 m

The vertical position of the projectile at time t is

$y = h + \frac{1}{2}at^2$

By requiring y = 0, we find the time t at which the projectile reaches the position y=0, which corresponds to the ground:

$0 = h + \frac{1}{2}at^2\\t=\sqrt{-\frac{2h}{a}}=\sqrt{-\frac{2(55.0 m)}{(-9.8 m/s^2)}}=3.35 s$

(b) 78.4 m

The distance travelled by the projectile from the base of the building to the point it lands depends only on the horizontal motion.

The horizontal motion is a uniform motion with constant velocity -

The horizontal velocity of the projectile is

$v_x = 23.4 m/s$

the time it takes the projectile to reach the ground is

t = 3.35 s

So, the horizontal distance covered by the projectile is

$d=v_x t = (23.4 m/s)(3.35 s)=78.4 m$

(c) 23.4 m/s, -32.8 m/s

The motion of the projectile consists of two independent motions:

- Along the horizontal direction, it is a uniform motion, so the horizontal velocity is always constant and it is equal to

$v_x = 23.4 m/s$

so this value is also the value of the horizontal velocity just before the projectile reaches the ground.

- Along the vertical direction, the motion is acceleration, so the vertical velocity is given by

$v_y = u_y +at$

where

$u_y = 0$ is the initial vertical velocity

Using

a = g = -9.8 m/s^2

and

t = 3.35 s

We find the vertical velocity of the projectile just before reaching the ground

$v_y = 0 + (-9.8 m/s^2)(3.35 s)=-32.8 m/s$

and the negative sign means it points downward.

3 0

3 years ago

Rita has two small containers, one holding a liquid and one holding a gas. Rita transfers the substances to two larger container

SVETLANKA909090 [29]

Sample Response: liquids flow freely, they take the shape of the container they are in, but have a definite volume. Like liquids, the shape of a gas changes with the container. This is because the atoms in a gas move rapidly and freely to fill any available space. Unlike liquids, the volume of a gas changes depending on the container it is in.

3 0

4 years ago

Read 2 more answers

Describe Earth's three global wind belts

fiasKO [112]

Polar Easterlies: From 60-90 degrees latitude.
Prevailing Westerlies: From 30-60 degrees latitude (aka Westerlies).
Tropical Easterlies: From 0-30 degrees latitude (aka Trade Winds).

4 0

3 years ago

1. Consider the point exactly halfway between the two wires. Can you adjust the current so that, with current passing through ea

chubhunter [2.5K]

Answer:

hello your question is incomplete attached below is missing part of the question

answer:

1 ) Magnetic field due to long current carrying wire : $B = \frac{U_{0} I}{2\pi d}$

Therefore the net magnetic field due the both wires ; B = B $_{1}$ + B $_{2}$ . when we adjust the current I $_{1}$ = I $_{2}$ then the Netfield (B ) = zero

2) The distance between the field lines are not equally spaced and this is because the separation between field lines increases with the increase in the distance between the wires

3) Increase in current through the wire will lead to increase in force and this can be explained via this equation

$F = \frac{U_{0}I_{1}I_{2} }{2\pi d }$

Explanation:

1 ) Magnetic field due to long current carrying wire : $B = \frac{U_{0} I}{2\pi d}$

Therefore the net magnetic field due the both wires ; B = B $_{1}$ + B $_{2}$ . when we adjust the current I $_{1}$ = I $_{2}$ then the Netfield (B ) = zero

2) The distance between the field lines are not equally spaced and this is because the separation between field lines increases with the increase in the distance between the wires

3) Increase in current through the wire will lead to increase in force and this can be explained via this equation

$F = \frac{U_{0}I_{1}I_{2} }{2\pi d }$

8 0

3 years ago