A radioactive isotope has a half-life of 20 hours. How long will it take for 3/4 of the source to decay?

Answers

Answer 1

Answer:

40 hours

Explanation:

in 20 hours, 1/2 will decay

in 40 hours, 1/4 will decay

therefore, 40 hours


Related Questions

Which frequencies can humans can hear but not mice

Answers

of approximately 1 to 4 kHz6 and approximately 16 kHz for mice.

if tje object is placed pf the focus of a concave mirror the image is formed....​

Answers

Answer:

when object is kept at focus then image will form at infinity

Explanation:

virtual erect highly diminished image will be formed and it is used in the lense in galilean telescope


The brakes of a lorry are in a poor condition
What effect will the condition of the brakes have on thinking distance and the braking
distance of the lorry?

Answers

Answer:

friction

Explanation:

Her brakes will squeak and possibly slide or skid on concrete due to her brakes.

BUT it really depends on the condition of the wheels. Now it matters on the surface as well. Has the road been eroded? what has happened with her brakes? and what texture are the wheels? can seismic waves travel through them?

Answer:

thinking distance stays the same and the braking distance increases

AQA Approved.✅

Explanation:

if a circuit has 3 A of current and a 5 ohm resistor, how many volts are powering the circuit

Answers

Answer:

Given =

Current = 3 A

Resistance = 5 ohm

Solution =

By Ohm's Law

R = V/I

V = R x I

V = 5 x 3

V = 15 volts. Answer

The heat from the sun travels to Earth___
A. In high-frequency waves
B.In low frequency-waves
C.Through the movement of molecules
D.By conduction and convention

Answers

Answer:

a in high frequency waves

Explanation:

because of the thermal radiation from the sun

Answer:

The answer is B, "In low frequency-waves"

Explanation:

I got this right on my lesson! Have a great day! (-;

A 8-kg load stretches an elastic belt 0.02 m. How much will a 12-kg load stretch the belt?

Answers

Answer:

0.06

Explanation:

a 6 load will be 0.03 so double it to get the answer which is 0.06

Which vector is the sum of the vectors shown below?

Answers

B.

The addition if vectors is commutative, so adding in any order will lead to the same result; just draw a straight line from the starting point to the tip of the final vector.
B is the sum of the vectors shows

13. A glass of water left in the sun becomes warm. Estella adds ice to the water to make
it cool. What energy change occurs when ice is added to the warm drink?

Answers

Answer:

second

Explanation:

second

I’m pretty sure The second one is the correct answer

Write two characteristics of an educated society ​

Answers

Answer:

Different and better?

Explanation:

i dont think that helps lol

An educated person has the ability to think clearly and independently and has good judgement.

What is Education?

Education is defined as purposeful activity directed towards achieving some objective, such as the dissemination of knowledge or the promotion of skills and character traits, whose aims include the development of understanding, rationality, kindness and honesty.

There are three main types of education which are as follows:

Formal, Informal and Non-formal.

The specialty of education is that it is pre-determined and pre-planned. It is regular and spatial i.e. time bound and regulated by the institutional. Proper education improves people's understanding of the world around them which make them less susceptible to the influence of others

Thus, an educated person has the ability to think clearly and independently and has good judgement.

Learn more about Education, here:

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Why is an electromagnet used instead of a permanent magnet in magnetic cranes?​

Answers

Answer:

an electromagnet is a metal which has the ability to turn into a magnet on passing electricity through it .

But once the electric flow is withdrawn the circuit breaks and it no more behaves like a magnet.

but this is not so in permanent magnets

Explanation:

thus electromagnet is used in magnetic cranes bcoz their magnetism can be controlled conveniently.

Newton’s first law of motion states that an object's motion remains the same unless a force acts upon it. What would be an example of this law in action?

Answers

Answer:

A driver breaks suddenly and the passengers are flung forward

write down the expressions for the heat produced per second in a resistor in terms of potential difference and resistance​

Answers

Answer:

[tex]H=\frac{V^2}{R}[/tex]

Explanation:

Let H be  heat produced per sec

Time, t=1 sec

Resistance of resistor=R ohm

We have to write down the expression for the  heat produced per second in a resistor in terms of potential difference and resistance​.

We know that

Heat, [tex]H=I^2 Rt=\frac{V^2}{R}t[/tex]

Substitute the value

Then, we get

Heat,[tex]H=\frac{V^2}{R}\times 1[/tex]

[tex]H=\frac{V^2}{R}[/tex]

This is required expression for the heat produced per second in a resistor  in terms of potential difference and resistance​.

Need help as fast as possible please
I will mark BRAINLIST only for correct answers babes :)
Thank you!

Answers

Regular reflections occurs when light reflects off a very smooth surface and forms a clear image.
Diffuse reflection: occurs when light reflects off a rough surface and forms a blurry image or no image at all.

Similarities: they both hit the surface, but the difference is one of them give clear image the other one gives blurry image or no image at all.

Hope this helped!

what happens as photons of visible light are absorbed by dye molecules?

Answers

Certain electrons in the dye molecule move to a higher energy level, with the difference in energy between the lower and higher energy levels being the same as the energy of the absorbed photons.

A 40.0 kg box is placed on a 2.00 m tall shelf. If the box falls off the shelf, what is its kinetic energy as it strikes the ground?

Answers

m = 40 Kg , g=9.8 m/s² , h = 2 m

PE = m g h

PE = (40) (9.8) (2)

PE = 784 J

KE = PE

½m v² = m g h

½ v² = g h

½ v² = (9.8) (2)

½ v² = 19.6

v² = 19.6×2

v² = 39.2

V = √39.2

V = 6.26 m/s

KE = ½mv²

KE = ½(40) (6.26)²

KE =783.8 J

An electric iron is connected to the mains power supply of 220 V. When the electric iron is

adjusted at 'minimum heating' it consumes a power of 360 W but at 'maximum heating' it takes a

power of 840 W. Calculate the current and resistance in each case.​

Answers

Answer:

Given: V = 220V, Pmin = 360W, Pmax = 840W

For minimum heating case:

We know that

Pmin = VI

360 = 220 X I

I = 1.63 amp

R = V/I

R = 220/1.63

R = 134.96ohms

For maximum heating case:

We know that

Pmax = VI

840 = 220 X I

I = 3.81 amp

R = V/I

R = 220/3.81

R = 57.74 ohms

please please please hellpppppppp!!!!!!

Answers

Answer:

The Answer is A

Explanation:

The answer I believe is A!

write down the expressions for the heat produced per second in a resistor in terms of current and resistance​

Answers

Answer:

Heat,[tex]H=I^2 R[/tex]

Explanation:

Let H be the heat produced

Time, t=1 sec

I=Current

R=Resistance of resistor

We have to write down the expressions for the heat produced per second in a resistor in terms of current and resistance​.

We know that

Heat, [tex]H=I^2 Rt[/tex]

Using the formula

Heat,[tex]H=I^2R\times 1[/tex]

Heat,[tex]H=I^2 R[/tex]

Hence, the the expressions for the heat produced per second in a resistor in terms of current and resistance​ is given  by

Heat,[tex]H=I^2 R[/tex]

The location where an earthquake begins

A. Strike-Slip fault

B. Epicenter

C. Focus

D. Seismogram

Answers

Answer:

b

Explanation:

the location where an earthquake begin is called

How does the value and direction of the restoring force change as the spring constant or displacement is changed?

Answers

Answer:

The effect of gravity is only to shift the equilibrium point, so at equilibrium (at rest), a vertical spring will be extended as compared with the same spring in a horizontal position. But this does not affect the period.

As  the spring constant or displacement is changed, the value and direction of the restoring force change, and they are always toward the equilibrium position of the spring when it is stretched.

What is the significance of the restoring force?

When an object is relaxed or stretched, it is responsible for returning it to its original equilibrium position, such as a spring when stretched, and the force is directly proportional to the displacement and acts in the opposite direction of the displacement, the restoring force is responsible for the oscillations and waves, and its properties.

Hence, as the spring constant or displacement is changed, the value and direction of the restoring force change, and they are always toward the equilibrium position of the spring when it is stretched.

Learn more about the restoring force here.

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001)
9. A ball is rolled at a velocity of 12 m/s. After 36 seconds, it comes to a stop. What is the acceleration of the ball?

Answers

Answer:

0.33333333333

Explanation:

a = v/t

= 12/36

= 1/3

= 0.3333

Answer:

3

Explain

36/12

when you come out of a river you feel cold. why?​

Answers

Answer:

the wind

Explanation:

A man who has type B blood (genotype: BB) is married to a woman with type O blood. What blood type will their children have? blood typing

Answers

Type BO or B because BBxOO would give you 100% BO which is BO or B

How does an air mattress protect a stunt person landing on the ground after a stunt?

Answers

Answer:

a) It reduces the kinetic energy loss of the stunt person.

An air mattress acts as a cushion of gas between the stunt person and the ground, absorbing part of the shock if the action person falls.

What is air mattress?

An air mattress is an inflated mattress composed of polyvinyl chloride (PVC) and textile-reinforced urethane plastic and rubber. It is also known as an airbed or even a blow-up bed. Deflated mattresses may be compressed and transported and stored in a tiny size.

An air mattress acts as a cushion of gas between the stunt person and the ground, absorbing part of the shock if the action person falls or if it is thrown from a great height. This shields the stunt performer from catastrophic dangers like shattered bones or concussions.

Therefore, an air mattress acts as a cushion of gas between the stunt person and the ground, absorbing part of the shock if the action person falls.

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Anyone able to help with these questions, will give brainliest to first correct anwser

Answers

Answer:

b

Explanation:

I did this question earlier

2.5 x 103 kilogram truck with rubber tires moves through a 120 meter radius turn on a dry asphalt surface.

a. Determine the force of friction acting on the truck's tires during the turn.


b. Calculate the maximum speed with which the truck could have made this turn.

Answers

Answer:

a. The friction force acting on the truck's tires during the turn, is approximately 20,875 N

b. The maximum velocity with which the truck could make the bend is approximately 31.654 m/s

Explanation:

The given parameters of the truck are;

The mass of the truck, m = 2.5 × 10³ kg

The tire material = Rubber

The radius of the turn the through which the truck moves = 120 meters

The material and condition of the surface = Dry asphalt

a. The coefficient of friction of rubber tires on dry asphalt, μ ≈ 0.85 (researchgate (internet source))

The weight of the truck, W = m × g

Where;

m = The mass of the truck = 2.5 × 10³ kg

g = The acceleration due to gravity = 9.8 m/s²

∴ W = 2.5 × 10³ kg × 9.8 m/s² = 24,500 N

The force of friction acting on the tires, [tex]F_f[/tex] = W × μ

∴ [tex]F_f[/tex] = 24,500 N × 0.85 ≈ 20,875 N

The friction force acting on the truck's tires during the turn, [tex]F_f[/tex] ≈ 20,875 N

b. The centrifugal force the truck observes while turning through the bend, 'F', is given as follows;

F = m·v²/r

Therefore, the maximum velocity with which the truck could make the bend, 'v', is given when fiction force, '[tex]F_f[/tex]', is equal to the centripetal force, F

When [tex]F_f[/tex] = F, we have;

W × μ = m·v²/r

∴ 20,875 N = 2.5 × 10³ kg × v²/(120 m)

∴ v² = 20,875 N × (120 m)/(2.5 × 10^3 kg) = 1002 m²/s²

v = √(1002 m²/s²) ≈ 31.654 m/s

The maximum velocity with which the truck could make the bend, v ≈ 31.654 m/s

The force of friction acting on the truck's tires during the turn is 20,875 NThe maximum velocity with which the truck could have made the turn is 31.654 m/s.

According to this question;

The mass of the truck (m) = 2.5 × 10³ kgThe radius of the turn = 120mThe coefficient of friction of rubber tires on dry asphalt, μ ≈ 0.85

QUESTION 1:

Weight of the truck (W) = m × g

Where;

m = mass of the truck = 2.5 × 10³ kgg = acceleration due to gravity = 9.8 m/s²

W = 2.5 × 10³ kg × 9.8 m/s² = 24,500 N

The force of friction acting on the tires, = W × μ

= 24,500 N × 0.85 ≈ 20,875 N

The force of friction acting on the truck's tires during the turn = 20,875 N

QUESTION 2:

Centrifugal force of the truck can be calculated as follows: F = mv²/r

However, force of friction (Ff) is equal to centripetal force (F). That is;

W × μ = m·v²/r

20,875N = 2.5 × 10³ kg × v²/(120 m)

v² = 20,875 × 120/2.5 × 10³ = 1002 m²/s²

v = √1002 = 31.654m/s

The maximum velocity with which the truck could make the turn = 31.654 m/s.

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pleaseeeeeeeeee helpppppppppppppppp

Answers

I feel like it could be A

What is the blank? (physics)
The total energy of a system is equal to the energy added to the system plus the work and the ____ that is produced.

Answers

Answer:

Heat???

Sorry I am not at all sure

32) In an electrical circuit the current is measured in
A) amps using an ammeter.

B) amps using a voltmeter.

C) volts using an ammeter.

D) volts using a voltmeter.

Answers

Answer:

A) amps using an ammeter.....

What causes moons to orbit planets and  planets to orbit stars

Answers

Answer:Orbits are the result of a perfect balance between the forward motion of a body in space, such as a planet or moon, and the pull of gravity on it from another body in space, such as a large planet or star. An object with a lot of mass goes forward and wants to keep going forward; however, the gravity of another body in space pulls it in.

Explanation:

Gravity, gravity is the force of attraction that everything has and is stronger when an object has more mass or is closer to something.
{ Search “gravity in space” to learn more. Hope it helps and have a good day!}
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