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3 years ago

What is an indicator?

1 answer:

4 0

The answer is A because An Indicator" changes color when it comes in contact with an acid or a base

An indicator could be anything like:
1) Litmus paper
2) Bromothymol blue
3) Phenolphthalein

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Pedro está realizando sus tareas de Física. Durante un descanso observa la goma de borrar y el lápiz sobre la mesa, y se pregunt

ahrayia [7]

Answer:

The gravitational force between these two objects is around $F_{g}=6.674*10^{-11} N$

Explanation:

The gravitational force can be written as:

$F_{g}=G\frac{m_{1}m_{2}}{r^{2}}$

Here:

G is the gravitational constant $G = 6.674*10^{-11} m^{3}kg^{-1}s^{-2}$
m(1) is the first mass
m(2) is the second mass
r is the distance between two bodies.

If we see, the gravitational constant is a very small number, therefore the gravitational force is representative just when we have to massive bodies. Let's suppose that the mass of the pencil is 0.1 kg and the eraser is 0.1 kg too, the distance between them would be around 10 cm or 0.1 m, for instance.

Now let's calculate the gravitational force of these two bodies.

$F_{g}=G\frac{0.01*0.01}{0.1^{2}}$

$F_{g}=6.674*10^{-11} N$

As we see it is very small force, so it is negligible relation to the earth gravitational force. That is why these two objects do not move towards each other.

I hope it helps you!

3 0

4 years ago

Match the term with the definition.

lutik1710 [3]

Answer:

A. Atom :- a substance that cannot be broken down into a simpler substance.

Explanation:

Atom is a basic unit of any chemical substance or element. It cannot be broken into simpler material. Although it is known that an atom is made up of electron proton and neutron but these are not simpler substances. In an atom electron is negatively charged and proton is positively, while neutron is neutral.

6 0

4 years ago

if a 5-kg bowling ball is projected upward witha velocity of 2.0 m/s, then what is the recoil velocity of the Earth(mass=6.0×10^

vitfil [10]

by the concept of momentum conservation we can say

if net force on a system of mass is ZERO then its momentum will remain conserved

Here a ball is projected upwards so if we take Ball + Earth as a system then total momentum of the system will remain conserved

Initially when ball is on the surface of earth the system has zero momentum and hence we can say after throwing the ball momentum of earth + ball must be zero

now using same equation we can say

$P_{ball} + P_{earth} = 0$

$m_1v_1 + m_2v_2= 0$

given that

$m_1 = 5 kg$

$v_1 = 2 m/s$

$m_2 = 6 * 10^{24} kg$

from above equation velocity of earth will be

$v_2 = \frac{m_1 v_1}{m_2}$

$v_2 = \frac{5*2}{6 * 10^{24}}$

$v_2 = 1.67 * 10^{-24} m/s$

so above will be the recoil speed of earth

3 0

3 years ago

Two lamps rated 60W; 240V and 100W, 240Vrespectively are connected in series to a 240V power source. Calculate;

nikdorinn [45]

Answer:

See the answers below.

Explanation:

The total power of the circuit is equal to the sum of the powers of each lamp.

$P=60+100\\P=160 [W]$

Now we have a voltage source equal to 240 [V], so by means of the following equation we can find the current circulating in the circuit.

$P=V*I$

where:

P = power [W]

V = voltage [V]

I = current [amp]

$I = P/V\\I=160/240\\I=0.67 [amp]$

So this is the answer for c) I = 0.67 [amp]

We know that the voltage of each lamp is 240 [V]. Therefore using ohm's law which is equal to the product of resistance by current we can find the voltage of each lamp.

$V=I*R$

where:

V = voltage [V]

I = current [amp]

R = resistance [ohms]

Therefore we replace this equation in the first to have the current as a function of the resistance and not the voltage.

$P=V*I\\and\\V = I*R\\P = (I*R)*I\\P=I^{2}*R$

$60 = (0.67)^{2}*R\\R_{60}=133.66[ohm] \\and\\100=(0.67)^{2} *R\\R_{100}=100/(0.66^{2} )\\R_{100}=225 [ohm]$

The effective resistance of a series circuit is equal to the sum of the resistors connected in series.

$R = 133.66 + 225\\R = 358.67 [ohms]$

7 0

3 years ago

Question 3 A woman sitting in a stationary car notices a man cycling past her at 40 km/hr. Five seconds after he passes her car,

Naya [18.7K]

The shortest possible distance in which she catches up with the man is 129.7 m.

The given parameters:

speed of the man, v₁ = 40 km/hr

speed of the woman, v₂ = 70 km/hr

time when the woman started moving, t₁ = 5 seconds

To find:

the shortest distance when she catches up with the man

Convert the given speed in km/h to m/s

3.6 km/h = 1 m/s
40 km/h = 40/3.6 = 11.11 m/s
70 km/h = 70/3.6 = 19.44 m/s

Calculate the distance moved by the man before she started following him.

Distance moved by the man = speed x time

= 11.11 m/s x 5 s

= 55.55 m

Let the time the woman catches up with the man = t

Apply the following simple principle to calculate the time.

The man is moving forward and the woman is moving forward to close the gap between them, thus both speeds are working against each other.

$(v_2-v_1)t = 55.55 \ m$

the difference in the speed is because they are working against each other.

$(19.44 - 11.11)t = 55.55\\\\8.33t = 55.55\\\\t = \frac{55.55}{8.33} \\\\t = 6.67 \ s$

The time when the woman catches up with the man = 6.67 s

The shortest distance at which the woman catches up with the man is calculated as;

Shortest distance = woman's speed x time when she catches up

= 19.44 m/s x 6.67 s

= 129.7 m

Thus, the shortest possible distance in which she catches up with the man is 129.7 m.

Learn more here: https://brainly.in/question/9541933?tbs_match=3

5 0

3 years ago