HELLLPPP
why didnt people in marie curies time realize radioactivity could be harmfull?
Answer:Health
Throughout her work with radium, Marie was unaware of the effects of radioactivity exposure on the body. In her lab, she would keep tubes of radium in her pocket. [3] She began to suspect that radium negatively impacted health when one of her fellow researchers died of a blood disease, and then a few years later her personal assistant died of a blood disease. Even though she suspected that radium exposure was bad for her health, she did very little to monitor her own blood. In 1932, she broke her wrist and the break took much longer to heal than it should have. She then began to notice that her vision was deteriorating and radiation burns on her fingers were becoming more and more painful. Some days she felt too ill to even go to the lab, and finally on July 4, 1934, Marie died from aplastic anemia. [1]
Radium Exposure Treatments
Marie suspected that her health was being negatively impacted by radium exposure, but did nothing about it, most likely because there weren't any effective treatments for radium poisoning yet. At the time, scientists knew that radium was metabolized like calcium. In an attempt to remove it from the system, they manipulated calcium intake. [4] This caused little to no improvements, so parathyroid hormone was added to the treatment. Again, there was some reduction of radium, but not a significant amount. It wasn't until after Marie's death that they realized once radium is in the bones, it is extremely difficult to extract. The lack of therapies for radium exposure may explain why Marie just ignored her symptoms, because she was fully aware of her fate. [4]
© Jenna Gray. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
Explanation:
Answer:
cause they were dumb
Explanation:
Imagine que su primo Morton baja en patineta por una rampa curva en un parque. Tratando a Morton y su patineta como una partícula, esta describe un cuarto de circulo de Radio= 3.00 m (ver figura) La masa total de Morton y su patineta es de 33 Kg. El parte del reposo y no hay fricción. Calcule su rapidez en la base de la rampa.
Answer:
Explanation:
We can solve this problem using the principle of conservation of energy.
Starting point. For higher up the ramp
Em₀ = U = m g h
where h is the height of the ramp h = 3.00 m
Final point. For low
Em_{f} = K = ½ m v²
as there is no friction the mechanical energy is conserved
Em₀ = [tex]Em_{f}[/tex]
m g h = ½ m v²
v = √ (2g h)
let's calculate
v = √(2 9.8 3.00)
v = 7.668 m / s
The 2020 Ford police interceptor has a max acceleration of 4.4 m/s2. If a policeperson is sitting on
the roadside when a speeding car passes them at 70 mph (31.3 m/s), and the policeperson takes off
at max acceleration 1 second later, will they be able to catch the speeder in 10 seconds?
(Show work)
Answer:
The policeperson will not be able to catch the speeder in 10 seconds
Explanation:
The maximum acceleration of the 2020 Ford police interceptor, a = 4.4 m/s²
The rate at which the speeding car is moving, v = 70 mph (31.3 m/s)
The time after which the policeperson takes off = 1 second
The time, t, at which the policeperson catches the speeding car is given as follows;
s = u·t + 1/2·a·t²
Where;
u = The initial velocity of the Ford police interceptor = 0
∴ s = 0 × t + 1/2·a·t² = 1/2·a·t²
s = 1/2·a·t²
s = v × (t + 1)
Equating both equations, gives;
v × (t + 1) = 1/2·a·t²
Substituting the values, we get;
31.3 × (t + 1) = 1/2 × 4.4 × t²
31.3·t + 31.3 = 2.2·t²
2.2·t² - 31.3·t - 31.3 = 0
By the quadratic formula, we have;
t = (31.3 ± √((-31.3)² - 4×2.2×(-31.3))/(2 × 2.2)
t ≈ -0.938 seconds or t ≈ 15.165 seconds
The policeperson will catch the speeder in approximately 15.165 seconds
Therefore, the policeperson will not be able to catch the speeder in 10 seconds.
A pelican flying along a horizontal path drops a fish from a height of 4 m. The fish travels 8.0 m horizontally before it hits the water below. What is the pelican’s speed
Pls solve to the fullest do not copy question and give very detail of how to do it pls and thank you
Answer:
Speed = 8.79m/s
Explanation:
Given the following data;
Height = 4m
Horizontal distance = 8m
To find the time, we would use the second equation of motion
S = ut + ½at²
We know that acceleration due to gravity is equal to 9.8m/s²
Initial velocity, u = 0
Substituting into the equation, we have;
4 = 0(t) + ½*9.8*t²
4 = 0 + 4.9*t²
4 = 4.9t²
t² = 4/4.9
t² = 0.82
Taking the square root of both sides, we have;
t = 0.91 secs
To find the speed;
Speed = horizontal distance/time
Speed = 8/0.91
Speed = 8.79m/s
Therefore, the pelican's speed is 8.79 meters per seconds.
Day and night are caused by
Answer:
The Moon rotating around Earth and the Earth rotating around the Sun
Explanation:
Answer:
the rotation of Earth on its axis
Explanation:
Did it on study island
Optimal cardiorespiratory fitness requires a BMI of __________.
A.
18.5 to 24.9
B.
25.0 to 29.9
C.
30.0 to 39.9
D.
40.0 to 49.9
Answer:
A
Explanation:
The car's initial speed was 32m / s and it takes 99 seconds for the car to come to a full stop after the driver applies the brakes. What is the magnitude of the car's acceleration?
Answer:
0.323232....m/s2
Explanation:
acceleration=V/t
32m/s/99s=0.3232m/s2
the Earth which is 150 million km from the Sun takes 365 days to complete one orbit assume the orbit to be in a circle find the length of the of the orbit giving your answer in standard form 2 correct to three significant figures
Answer:
Orbit/circumference = 471.24 million .
c = 2πr
150/2 = radius
radius = 75.
π = 3.14
2 x π x 75 = 471.24
Can someone help me in physics
Your best friend has very low energy levels and complains of not being able to sleep at night. Determine the BMI score that would most likely contribute to this problem.
14
20
22
23
Answer: 14
Explanation: 20-23 is normal.
Answer:14
Explanation:hope this helps
What change of state occurs during vaporization? liquid to gas gas to liquid solid to liquid liquid to solid
Answer:
A is correct!
Explanation:
e2020
Answer:
a
Explanation:
right on edge :)
A small convex mirror is placed 60 cm from the pole and on the axis of a large concave mirror of radius of curvature 200 cm. The position of the convex mirror is such that a real image of distant object is formed on the plane of a hole drilled through the concave mirror at its pole. Calculate 'R' of convex mirror and height of the real image if distant object forms 0.5 degree angle at the pole of the concave mirror.
Answer:
Calculate 'R' of convex mirror and height of the real image
the radius of the convex mirror is 48cm
Explanation:
Distance between convex and concave mirror is =60cm
Radius of the concave mirror (R) = 200cm
For the concave mirror, u = ∞
V = {R}/{2}=100cm
The object for the convex mirror and the final image is on the pole of the concave mirror, and distance between convex and concave mirror is 60cm
u_1=60-100 =-40cm
Object will be behind the convex mirror
1/f=1/40+1/60
f=24cms
the radius of the convex mirror is 48cm
fnet = fa + ff or fnet = fa - ff
Answer:first of all what is your question and i can give and example which is Use them when you have 2 forces named Fa & FF or Fg & Ff acting in opposite directions on an object and you need to know the resultant of your 2 forces.
Explanation:
i searched it up
According to the Big Bang Theory, the known universe started 13.7 billion years ago in a hot dense state and expanded explosively. As it expanded, it cooled down to the point where atoms could form. By the force of gravity, these atoms coalesced into gas clouds that eventually became stars. These stars eventually formed young galaxies. Which of the following is true about the current position of the galaxies in the universe?
A.
The galaxies are now drifting further apart.
B.
The position of the galaxies cannot be predicted.
C.
The galaxies are now moving closer together.
D.
The position of the galaxies is not changing.
Answer:
A
Explanation:
Hubble’s law states that galaxies that are farther away have a greater red shift, so the speed at which a galaxy is moving away is proportional to its distance from the Earth. Red shift is a phenomenon due to Doppler shifting, so the shift of light from a galaxy to the red end of the spectrum indicates that the galaxy and the observer are moving farther away from one another. Doppler shifting also is found in the Energy and Waves section of this course.
Which of the following does not correctly describe the position of the turtle and why?
Answer:
C. 2m to the right of the rollerblader
Explanation:
The turtle is 2m to the LEFT of the rollerblader, so its the only option not describing the position of the turtle:)
Hope this helps, have a great day;)
A 49 kg person is being dragged in their sleeping bag to the lake by a 593 N
force at an angle of 30°. If the person accelerates at a rate of 0.57 m/s?, how
much resistive force (force of friction) is acting on them?
NEED HELP LIKE RIGHT NOW PLz
Answer:
f = 485.62 N
Explanation:
Since, the bag is moving with some acceleration. Hence, the unbalanced force will be given as:
Unbalanced Force = Horizontal Component Applied Force - Frictional Force
Unbalanced Force = Fx - f
But, from Newtons Second Law of Motion:
Unbalanced Force = ma
comparing the equations:
ma = Fx - f
f = F Cos θ - ma
where,
f = frictional force = ?
F = Applied force = 593 N
m = mass of person = 49 kg
a = acceleration = 0.57 m/s²
θ = Angle with horizontal = 30°
Therefore,
f = (593 N)(Cos 30°) - (49 kg)(0.57 m/s²)
f = 513.55 N - 27.93 N
f = 485.62 N
What does the number of protons tell us about an element?
Answer:
All atoms of an element have the same number of protons, and every element has a different number of protons in its atoms. ... Therefore, the atomic number of an atom also tells you how many electrons the atom has. This, in turn, determines many of the atom's chemical properties.
The greater the___of the object, the greater the force needed to achieve the same change in motion.
Answer:mass
Explanation:
You are piloting a helicopter which is rising vertically at a uniform velocity of 14.70 m/s. When you reach 196.00 m, you see Barney (Uh-oh). A large object is projected with a horizontal velocity of 8.50 m/s from the rising helicopter. When does the ball reach Barney's head if he is standing in a hole with his head at ground level?
Answer:
The ball reaches Barney head in [tex]t = 8 \ s[/tex]
Explanation:
From the question we are told that
The rise velocity is [tex]v = 14.70 \ m/s[/tex]
The height considered is [tex]h = 196 \ m[/tex]
The horizontal velocity of the large object is [tex]v_h = 8.50 \ m/s[/tex]
Generally from kinematic equation
[tex]s = ut + \frac{1}{2} gt^2[/tex]
Here s is the distance of the object from Barney head ,
u is the velocity of the object along the vertical axis which is equal but opposite to the velocity of the helicopter
So
[tex]u = -14.7 m/s[/tex]
So
[tex]196 = -14.7 t + \frac{1}{2} * 9.8 * t^2[/tex]
= [tex]4.9 t^2 - 14.7t - 196 = 0[/tex]
Solving the above equation using quadratic formula
The value of t obtained is [tex]t = 8 \ s[/tex]
A car speeds up from 14 meters per second to 21 meters per second in 6 seconds. Whats the acceleration and the distance passed within that time?
Answer:
a = 1.666... m/s²
Explanation:
a = v2 - v1 / t2 - t1
a = 21m/s - 14m/s / 6s - 0s
a = 7m/s / 6s
a = 1.666... m/s²
What training does an osteologist need? (ANATOMY)
Answer:
Requirements to become an Osteologist
Explanation:
After completing the bachelor's degree, students should begin working towards a master's degree or Ph. D specializing in forensic anthropology. Forensic anthropology is closely related to osteology and it will help in the forensic work.
What if the Earth was moved out to Jupiter's orbit which is about 5
times further from the Sun that Earth. How would the Sun's effect on
the Earth change at that distance?
25 times less gravitational force
0.5 times less gravitational force
5 time less gravitational force
Answer:
25.0 less force
Explanation:
If an object is in motion, then the object will ______
because ______________________.
Answer:
If an object is in motion, then the object will stay in motion because they go the same direction unless acted upon by an unbalanced force.
Explanation:
i got it right . :)
Why is it hard to respond with action at times?
The acceleration due to gravity on Earth is 9.8 m/s2. What is the weight of a 75 kg person on Earth? 9.8 N 75 N 85 N 735 N
The weight of a 75 kg person on Earth is 735 N, The correct option is D.
What is the acceleration due to gravity?Acceleration due to gravity is the acceleration that an object experiences due to the gravitational force exerted by a massive body, such as Earth. The acceleration due to gravity on Earth is approximately 9.8 meters per second squared (m/s^2) and is denoted by the symbol "g".
The acceleration due to gravity is a vector quantity, which means that it has both magnitude and direction. The direction of the acceleration due to gravity is always downwards, towards the center of the massive body.
The acceleration due to gravity is a constant value near the surface of the Earth, but it can vary slightly depending on altitude, latitude, and the composition of the Earth's interior. For example, at higher altitudes, the acceleration due to gravity decreases slightly, while at the equator, it is slightly greater than at the poles due to Earth's rotation.
The acceleration due to gravity plays an important role in many physical phenomena, including free fall, projectile motion, and the behavior of fluids in containers.
Here in the Question,
The weight of a 75 kg person on Earth can be calculated using the formula:
weight = mass x acceleration due to gravity
Substituting the given values, we get:
weight = 75 kg x 9.8 m/s^2
weight = 735 N
Therefore, the weight of a 75 kg person on Earth is 735 N, which is option D.
To learn more about Gravitational force click:
brainly.com/question/29190673
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Danielle is applying 25.2 N to the right on her sled. The sled has a mass of 15.7 kg, and
is accelerating across the snow at a rate of 1.35 m/s2.
What is the magnitude of the normal force?
a. 4.00 N
b. 13.57 N
C. 11.63 N
d. 153.86 N
The applied force is parallel to the ground, so the net vertical force on the sled is 0. By Newton's second law, this means the normal force and weight of the sled cancel out:
n - w = 0
n = w
n = m g
n = (15.7 kg) (9.80 m/s²)
n = 153.86 N
pls help asap plsss
What is your hypothesis (or hypotheses) for this experiment?
Answer: In that case, Put something like "My hypothesis is that the car will take (x) seconds to get to checkpoint 1, (x) seconds to get to checkpoint 2, (x) seconds to get to checkpoint 3, and (x) seconds to get to checkpoint 4" Replacing x with random numbers, or number close to the actual found numbers, but honestly as long as the guesses arent outrageous you should get the question right
Explanation:
I formulate a hypothesis which is based on his observations as to what happens when both the rock and the wood are immersed in water.
What is Density?Density is described as mass per unit volume which is an important parameter for understanding fluid and its properties. Its unit is kilogram per cubic meter.
The mass and density relation is given as:
mass = density × volume
In this scientific investigation if the volume or density of objects determines whether solid objects float or sink in water, I performed a density, mass, and volume experiment using a rock and a standard-sized piece of wood. It is important that the chosen piece of wood is larger than the rock where the rock is small enough to fit inside the measuring cylinder.
Thus, I formulate a hypothesis which is based on his observations as to what happens when both the rock and the wood are immersed in water.
Learn more about the Density, here:
brainly.com/question/952755
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Your question is incomplete, most probably the complete question is:
Density of solids What is your hypothesis (or hypotheses) for this experiment?.
what are the kinetic energy
Answer:
n physics, the kinetic energy (KE) of an object is the energy that it possesses due to its motion.[1] It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes. The same amount of work is done by the body when decelerating from its current speed to a state of rest.
In classical mechanics, the kinetic energy of a non-rotating object of mass m traveling at a speed v is {\displaystyle {\begin{smallmatrix}{\frac {1}{2}}mv^{2}\end{smallmatrix}}}{\begin{smallmatrix}{\frac {1}{2}}mv^{2}\end{smallmatrix}}. In relativistic mechanics, this is a good approximation only when v is much less than the speed of light.
The standard unit of kinetic energy is the joule, while the imperial unit of kinetic energy is the foot-pound.
Explanation:
Answer:
kinetic energy is the energy that an object posses due to their motions.
Explanation:
eg:When you let go of that ball and let it fall, the potential energy converts into kinetic energy, or the energy associated with motion. There are five types of kinetic energy: radiant, thermal, sound, electrical and mechanical.
proof of conservation of energy