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Reika [66]
3 years ago
13

What is half-life? a. Half-life is a term that describes the time it takes for half of a particle to disintegrate c. Half-life i

s a term that describes the time it takes for the amount of radioactivity to increase by one half. b. Half-life is a term that describes the time it takes for the amount of radioactivity to go down by one half. d. None of the above
Physics
1 answer:
Alisiya [41]3 years ago
4 0
Well, half-life is the radioactivity of an identified isotope that decreases by half of the actual value.
So, your answer would be C. 
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Tarzan and Jane. Because of your concern that incorrect science is being taught to children when they watch cartoons on TV, you
creativ13 [48]

Answer:

The maximum height Tarzan and Jane can swing as a fraction of her initial heigh is ⅓h

Explanation:

Let

m = Mass of Tarzan

M = Mass of Jane

Given

M = 2m

To calculate the maximum height Tarzan and Jane can swing, we make use of the potential energy at their initial and final position.

Reason being that;

At both the initial and final position, velocity is 0, so there's no kinetic energy.

And the potential energy remains the same (i.e constant) at any given point in the system.

Using P.E = mgh.

At initial position, PE1 = mgh

At final position, PE2 = (m + M)gH.

Where h and H represent the initial and final heights.

m + M is the new weight after Jane and Tarzan swing

Equating PE1 to PE2

mgh = (m + M)gH

By substituton (M = 2m)

mgh = (m + 2m)gH

mgh = 3mgH

Make H the subject of the formula

H = mgh/3mg

H = ⅓h

Hence, the maximum height Tarzan and Jane can swing as a fraction of her initial heigh is ⅓h

From the question, the new height looks to be about ½ that of Jane's original position; i.e. ½h

The calculated height is smaller than what the cartoon is showing;

We can conclude that the cartoon is wrong.

4 0
2 years ago
As a woman walks, her entire weight is momentarily placed on one heel of her high-heeled shoes. Calculate the pressure exerted o
astraxan [27]

Answer:

3.6 x 10⁶ Pa

Explanation:

A = Area of the heel = 1.50 cm² = 1.50 x 10⁻⁴ m²

m = mass of the woman = 55.0 kg

g = acceleration due to gravity = 9.8 m/s²

Force of gravity on the heel is given as

F = mg

Inserting the values

F = (55) (9.8)

F = 539 N

Pressure exerted on the floor is given as

P = \frac{F}{A}

P = \frac{539}{1.5\times 10^{-4}}

P = 3.6 x 10⁶ Pa

6 0
3 years ago
An object is dropped from the top of a building and is observed to take 7. 2s to hit the ground. How tall is the building?.
maw [93]

the height of the building is H=36 m.

<h3>What is The Law of Gravity?</h3>

According to Newton's law of gravity, every particle of matter in the universe is attracted to every other particle with a force that varies directly as the product of their masses and inversely as their distance from one another.

Properties of Gravity -

  • It is a universal attractive force. It is directly proportional to the product of the masses of the two bodies.
  • It obey inverse square law.
  • It is the weakest force known in nature.

Examples of Gravity -

  • The force that holds the gases in the sun.
  • The force that causes a ball you throw in the air to come down again.
  • The force that causes a car to coast downhill even when you aren't stepping on the gas.

v₀=0 m/s

H₀=0 m

g=10 m/s²

t=7,2 s

H - ?

H= H_{0} + v_{0}t+\frac{gt^{2} }{2}   \\

H = 0 +0 × 7.2 + 10(7.2)²/2

H = 36m

to learn more about Gravity go to - brainly.com/question/12528243

#SPJ4

8 0
1 year ago
A 20.0 kg crate sits at rest at the bottom of a 15.0-m-long ramp that is inclined at 34.0° above horizontal. A constant horizont
ankoles [38]

Answer:

987 joules, 3.01s

Explanation:

(A)

from the attached diagram

net force, Fnet, pulling the crate up the ramp is given by

Fnet = FcosФ - WsinФ - Fr

where FcosФ is the component of horizontal force 290N resolved parallel to the plane

WsinФ = mgsinФ = component of the weight of the crate resolved parallel to the plane

Fr = constant opposing frictional force

Fnet = 290cos34⁰ - 20 × 9.8 × sin34° - 65

Fnet = 240.421 - 109.602 - 65

Fnet = 65.82N

Work done on the crate up the ramp, W, is given by

W = Fnet × d (distance up the plane)

W = 65.819 × 15

W = 987.285 joules

W = 987 joules (to 3 significant Figures)

(B)

to calculate the time of travel up the ramp

we use the equation of motion

s = ut + \frac{1}{2}at^{2}

where s = distance up the plane, 15m

u = Initial velocity of the crate, which is 0 for a body that is initially at rest

a = acceleration up the plane, given by

a = \frac{Fnet}{m}

where m = mass of the crate, 20 kg

now, a = \frac{65.819}{20} \\a = 3.291\frac{m^{2} }{s}

from, s = ut + \frac{1}{2}at^{2}

15 = 0*t + \frac{1}{2}* 3.291 * t^{2}

15 = 0 + 1.645t^{2}

15 = 1.645t^{2}

t = \sqrt{\frac{15}{1.645} }

t = 3.019

t = 3.01s (to 3 sig fig)

7 0
3 years ago
What type of rays would you expect to be used frequently at a hospital to make medical diagnoses?
Bess [88]
X rays because to see your bones
7 0
3 years ago
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