Answer:
False
Explanation:
All the lanthanides are not radioactive in nature. Just one of the lanthanides are radioactive.
The lanthanides belong to the f-block on the periodic tableOnly Promethium in this group are radioactive in nature. Other elements in the lanthanide series might have radioactive isotopes.If the magnetic field of an electromagnetic wave is in the x-direction and the electric field of the wave is in the y-direction, the wave is traveling in the
Answer:
wave is in the y-direction, the wave is traveling in the
Explanation:
A rotating wheel requires 8.00 s to rotate 27.0 revolutions. Its angular velocity at the end of the 8.00-s interval is 99.0 rad/s. What is the constant angular acceleration (in rad/s) of the wheel?
Answer:
∝ = 28.92 rad/s²
Explanation:
Applying third equation of motion to the angular motion, we have:
2∝θ = ωf² - ωi²
where,
∝ = angular acceleration = ?
θ = angular displacement = (27 rev)(2π rad/1 rev) = 169.64 rad/s
ωf = final angular velocity = 99 rad/s
ωi = initial angular velocity = 0 rad/s
Therefore,
(2)∝(169.64 rad) = (99 rad/s)² - (0 rad/s²)
∝ = (9801 rad²/s²)/(38.8 rad)
∝ = 28.92 rad/s²
Which is an example of a chemical change?
The half-life of a substance is 10 years. What percent of the substance remains after 2 half-lives.
need answer asap. i think its 2.5 but not sure
Answer:
i think its 2.5 as well
Explanation:
What is the key variable for calculating potential energy?
Which is the MOST accurate description of this type of cell?
O A) It is a eukaryotic cell.
OB) It is a prokaryotic cell.
OC) It does not contain DNA.
OD) It does not contain a membrane-enclosed nucleus.
helpppppppp first person who answers gets a brainly if it’s right
It would be
O A) It is a eukaryotic cell.
The achilles tendon is subjected to a large tension stress that results in a strain of 6%. if the unloaded tendon is 10 cm long, how much does it elongate as a result of this strain?
The answer is .6cm I need to understand the work to get here.
Answer: 0.6cm
Explanation:
Strain is defined as how much an object can be stretched or deformed when force is applied to it . it measures the fractional change of the object’s length when the object faces tensional stress. It is calculated by using the formulae
Strain = ΔL/ L
where strain = 6%
L= Original length
ΔL= change in length
6% = ΔL/ 10 cm
ΔL= 10cm X 0.06
ΔL=0.6cm
A basketball has a coefficient of restitution of 0.821 in collisions with the wood floor of a basketball court. The ball is dropped on such a floor from a height of 2.07 m . How high is its fourth bounce?
Answer: The height of its fourth bounce = 0.43m
Explanation:
The coefficient of restitution denoted by (e), is the ratio that shows the final velocity to initial relative velocity between two objects after collision
IT is given by the formula in terms of height as
Coefficient of Restitution, e = √(2gh))/√(2gH) = √(h/H)
Where
Coefficient of Restitution, e= 0.821
H = 2.07 m
At fourth bounce , we have that
Coefficient of Restitution, e⁴ =√(h₄/H)
Putting the given values and solving , we have,
e⁴ =√(h₄/H)
= 0.821⁴ = √(h₄/2.07)
(0.821⁴ )² =h₄/2.07
0.2064 x 2.07 = 0.427 = 0.43
At fourth bounce, h₄ height = 0.43m
According to Ohm’s law, which combination of units is the same as the unit for resistance? volt ÷ ampere ampere × volt volt + ampere ampere ÷ volt
Answer:
volt ÷ ampere
Explanation:
The mathematical form of Ohms law is given by :
V = IR
Where V is voltage
I is current
R is resistance
[tex]R=\dfrac{V}{I}[/tex]
The unit of voltage is volt and that of current is ampere
Unit of resistance :
[tex]R=\dfrac{\text{volt}}{\text{ampere}}[/tex]
So, volt ÷ ampere is the same as the unit of resistance. Hence, the correct option is (a).
Answer:
The answer is: volt ÷ ampere
Explanation:
Hope this helps. :)
If it's right, can you mark me as Brainliest.
A jet plane flying 600 m/s experiences an acceleration of 4.0 g when pulling out of the circular section of a dive. What is the radius of curvature of this section of the dive?
Answer:
The radius is [tex]r = 9183.7 \ m[/tex]
Explanation:
From the question we are told that
The speed of the jet plane is [tex]v = 600 \ m/s[/tex]
The acceleration is [tex]a = 4g[/tex] here [tex]g = 9.8 \ m/s^2[/tex] so [tex]a = 4* 9.8 = 39.2 \ m/s^2[/tex]
Generally the centripetal acceleration of the jet just before it pulled out of the circular section dive is mathematically represented as
[tex]a = \frac{v^2}{r}[/tex]
=> [tex]r = \frac{v^2}{a}[/tex]
=> [tex]r = \frac{600^2}{39.2}[/tex]
=> [tex]r = 9183.7 \ m[/tex]
What would happen if there was a sudden increase in the amount of greenhouse gases in Earth’s atmosphere?
Earth would suddenly cool down because more heat would leave the Earth system and go back to space.
Earth would suddenly cool down because solar radiation would not be able to flow through the atmosphere.
Earth would suddenly warm up because more heat from the atmosphere would be radiated toward Earth’s surface.
Earth would suddenly warm up because more heat from the Sun would be allowed to enter the atmosphere.
Answer:
Earth would suddenly warm up because more heat from the Sun would be allowed to enter the atmosphere.
Explanation:
The greenhouse gasses would make the ozone layer thinner letting in more harmful rays on the sun.
Hope this helps!! :)
Also I need one more brainliest if you dont mind giving it to me :)
Answer:
Earth would cool down because it would reflect more solar radiation. it would be A.
Explanation:
A 50-g ball moving at 10 m/s in the +x direction suddenly collides head-on with a stationary ball of mass 100 g. If the collision is perfectly elastic, what is the velocity of each ball immediately after the collision?A. +6.7 m/s, -3.3 m/sB. -6.7 m/s, +3.3 m/sC. +3.3 m/s, -6.7 m/sD. -3.3 m/s, +6.7 m/s
Answer:
3.33m/sExplanation:
Using the law of conservation of momentum
m1u1 + m2u2 = (m1+m2)v
m1 and m2 are the masses of the object
u1 and u2 are the velocities
v is the final velocity
Given
m1 = 50g
u1 = 10m/s
m2 = 100g
u2 = 0m/s (stationary ball)
Required
Common velocity v
Substitute
50(10) + 100(0) = (50+100)v
500 = 150v
v = 500/150
v = 3.33m/s
Hence the velocity of each ball immediately after the collision is 3.33m/s
A skateboarder is moving at 2.00m/s and increases his velcity at a rate of 1.6m/s/s for 6.0 seconds. What is the displacement of the skateboarder during this game? Must include Given, Find , and Equation. Show all work .
Answer:
S = 40.8m
Explanation:
Given the following data;
Initial velocity, u = 2m/s
Acceleration, a = 1.6m/s²
Time, t = 6secs
Required to find the displacement
Displacement, S = ?
The displacement of an object is given by the second equation of motion;
[tex] S = ut + \frac {1}{2}at^{2}[/tex]
Where;
S represents the displacement measured in meters. u represents the initial velocity measured in meters per seconds. t represents the time measured in seconds. a represents acceleration measured in meters per seconds square.Substituting into the equation, we have;
[tex] S = 2*6 + \frac {1}{2}*(1.6)*6^{2}[/tex]
[tex] S = 12 + 0.8*36[/tex]
[tex] S = 12 + 28.8 [/tex]
S = 40.8m
Therefore, the displacement of the skateboarder during this game is 40.8 meters.
What 2 things define the state of matter?
Answer:
mass and volume
Explanation:
matter is anything that has mass and occupies space(volume)
Answer:
Four states of matter are observable in everyday life: solid, liquid, gas, and sometimes plasma.
Shape is a characteristic property of matter.
The amount of matter in an object doesn't really affect the characteristic properties of the object
Explanation:
Please help me!!!
How much force is required to launch a 1 kg pumpkin 10 meters away from 5 meters off the
ground at a launch angle of zero degrees if it takes the catapult 0.1 seconds to fully launch the
pumpkin?
Answer:
F= 99 N
Explanation:
Dynamics and Kinematics
This problem is a combination of dynamics and kinematics because we need formulas and concepts of both branches of physics to solve it.
We need to calculate the force required to launch horizontally a pumpkin of m=1 Kg a distance of d=10 m away from a height of h=5 m.
Since the force is:
F = m.a
We need to calculate the acceleration required to move the pumpkin from rest (vo=0) to the launching speed (vf) in a time t=0.1 seconds.
The acceleration can be calculated by using the kinematic equation:
[tex]\displaystyle a=\frac{v_f-v_o}{t}[/tex]
The final launching speed vf can be calculated knowing the height and maximum horizontal distance reached by the pumpkin.
When an object is thrown horizontally with a speed vf from a height h, the range or maximum horizontal distance traveled by the object can be calculated as follows:
[tex]\displaystyle d=v_f\cdot\sqrt{\frac {2h}{g}}[/tex]
Solving for vf:
[tex]\displaystyle v_f=d\cdot\sqrt{\frac {g}{2h}}[/tex]
Substituting:
[tex]\displaystyle v_f=10\cdot\sqrt{\frac {9.8}{2\cdot 5}}[/tex]
Calculating:
[tex]v_f=9.9\ m/s[/tex]
Now we calculate the acceleration:
[tex]\displaystyle a=\frac{9.9-0}{0.1}[/tex]
[tex]a= 99\ m/s^2[/tex]
Thus, the force required is:
[tex]F=1\ Kg\cdot 99\ m/s^2[/tex]
F= 99 N
which of the following is an example of projectile motion?
a) a child tumbling down a hillside
b) a bowler rolling her ball down an alley
c) a football in flight during a field goal
d) a surfer riding a wave
In a two-slit experiment using coherent light, the distance between the slits and the screen is 1.10 m, and the distance between the slits is 0.0400 mm. If the second order bright fringe is measured to be 4.20 cm from the centerline on the screen, what is the wavelength of light?
A) 620 nm
B) 200 nm
C) 401 nm
D) 763 nm
E) 381 nm
Answer:
D) 763 nm
Explanation:
Calculation for the wavelength of light
Using this formula
Wavelength of light=Delta Y*Distance / Length
Where,
Delta Y represent the 2nd order bright fringe
Length represent the distance between both the slits and the screen
Distance represent the Distance between the slits
Let note that cm to m = (4.2) x 10^-2 and mm to m= ( 0.0400x 10^-3)
Now Let plug in the formula
Wavelength of light=[(4.2 x 10^-2m)(0.0400 x 10^-3m) / 2(1.1m)]*10^-7 meters
Wavelength of light=[(0.042m) (0.0004m)/2.2m]*10^-7 meters
Wavelength of light =(0.0000168m/2.2m)*10^-7 meters
Wavelength of light =7.63 *10^-7 meters
Wavelength of light =763 nm
Therefore the Wavelength of light will be 763 nm
If John throws a "ball” from a cliff with a speed of 15 m/s, how far from the bottom of the cliff does it land after 10 seconds?
Answer:
wazzam blood
Explanation:
A horizontal force of 100 N is required to push a 50 kg crate across a factory floor at a constant speed. What is the acceleration on the cart?
Answer:
a = 2m/s^2
Explanation:
Force (F) = 100 N
Mass (m) = 50 kg
Here,
F = m×a
100 = 50 × a
a = 100÷50
a = 2m/s^2
Thus, the acceleration on the cart is a = 2m/s^2
-TheUnknownScientist
2). If you record a wave going 4m/s and the Period of the wave was
60s, how long was the wave?
Answer:240 meters
Explanation:60×4
Telephone signals are often transmitted over long distances by microwaves. What is the frequency of microwave radiation with a wavelength of 3.5 cm?
Express your answer in GHz and using two significant figures.
f = ________GHz
Microwave signals are beamed between two mountaintops 52 km apart. How long does it take a signal to travel from one mountaintop to the other?
Express your answer in ms and using two significant figures.
t = ________ms
Answer:
1) f= 8.6 GHz
2) t= 0.2 ms
Explanation:
1)
Since microwaves are electromagnetic waves, they move at the same speed as the light in vacuum, i.e. 3*10⁸ m/s.There exists a fixed relationship between the frequency (f) , the wavelength (λ) and the propagation speed in any wave, as follows:[tex]v = \lambda * f (1)[/tex]
Replacing by the givens, and solving for f, we get:[tex]f =\frac{c}{\lambda} =\frac{3e8m/s}{0.035m} = 8.57e9 Hz (2)[/tex]
⇒ f = 8.6 Ghz (with two significative figures)
2)
Assuming that the microwaves travel at a constant speed in a straight line (behaving like rays) , we can apply the definition of average velocity, as follows:[tex]v =\frac{d}{t} (3)[/tex]
where v= c= speed of light in vacuum = 3*10⁸ m/s
d= distance between mountaintops = 52 km = 52*10³ m
Solving for t, we get:[tex]t = \frac{d}{c} = \frac{52e3m}{3e8m/s} = 17.3e-5 sec = 0.173e-3 sec = 0.173 ms (4)[/tex]
⇒ t = 0.2 ms (with two significative figures)
In a binary star system, the average separation between the stars is 5.0 AU, and their orbital period is 5.0 years. What is the sum of their two masses?The average distance of Star A from the center of mass is four times that of Star B. What are their individual masses?
Answer:
A. 5.03 solar mass.
B. the masses of Star A and B are 1.01 solar mass and 4.02 solar mass respectively.
Explanation:
A. The sum of their two masses can be found using Kepler's third law:
[tex]\frac{P^{2}}{a^{3}} = \frac{4\pi^{2}}{G(m_{A} + m_{B})}[/tex]
Where:
P: is the period = 5 y = 1.58x10⁸ s
a: is the separation between the stars = 5 AU = 7.5x10¹¹ m
G: is the gravitational constant = 6.67x10⁻¹¹ m³kg⁻¹s⁻²
[tex]m_{A}[/tex] and [tex]m_{B}[/tex] are the masses of Star A and Star B respectively.
[tex]m_{A} + m_{B} = \frac{4\pi^{2}a^{3}}{P^{2}G} = \frac{4\pi^{2}(5 AU*\frac{1.5\cdot 10^{11} m}{1 AU})^{3}}{(1.58 \cdot 10^{8} s)^{2}6.67 \cdot 10^{-11} m^{3}*kg^{-1}*s^{-2}} = 1.00 \cdot 10^{31} kg*\frac{1 M_{\bigodot}}{1.989\cdot 10^{30} kg} = 5.03 M_{\bigodot}[/tex]
Hence, the sum of their two masses is 5.03 solar mass.
B. Their individual masses can be found using the center of the mass equation:
[tex] a_{B} = (\frac{m_{A}}{m_{A} + m_{B}})a [/tex]
Where:
[tex]a_{B}[/tex] is the distance of Star B from the center of the mass
Since, [tex]a_{A}[/tex] is four times [tex]a_{B}[/tex] and a = 5 AU we have:
[tex] a_{A} = 4a_{B} [/tex]
[tex] a = a_{A} + a_{B} [/tex]
[tex] a_{B} = a - a_{A} = a - 4a_{B} \rightarrow a_{B} = \frac{a}{5} [/tex]
Then, their individual masses are:
[tex]\frac{a}{5} = (\frac{m_{A}}{5.03 M_{\bigodot}})a[/tex]
[tex]m_{A} = \frac{5.03 M_{\bigodot}}{5} = 1.01 M_{\bigodot}[/tex]
Now, the mass of Star B is:
[tex]m_{B} = m_{T} - m_{A} = 5.03 M_{\bigodot} - 1.01 M_{\bigodot} = 4.02 M_{\bigodot}[/tex]
Therefore, the masses of Star A and B are [tex]1.01 M_{\bigodot}[/tex] and [tex]4.02 M_{\bigodot}[/tex] respectively.
I hope it helps you!
uses of concave lens
Answer:
Concave Lens Uses. Telescope and Binoculars Spectacles Lasers Cameras FlashlightsPeepholes. ...
Used in telescope and binoculars. ...
Concave lens used in glasses. ...
Uses of concave lens in lasers. ...
Use of concave lens in cameras. ...
Used in flashlights. ...
Concave lens used in peepholes.
1. Which is true about atmospheric convection
currents?
A. Heat is released from the oceans and land causing wind.
B. Wind is only caused by the rotation of the Earth.
C. Wind is caused by the polar ice caps
D. Wind is caused by the gravity of planets in our solar system.
Answer:
A. heat is released from the ocean and land causing wind.
An object at rest will stay at rest, and an object in motion will stay in
motion, unless acted upon by an unbalanced force is known as which Law
of Motion?
Answer:
It is Newton's first law of motion also referred to as the law of inertia.
Explanation:
Does the weight of the projectile affect the horizontal range?
Answer:
no
Explanation:
This downward force and acceleration results in a downward displacement from the position that the object would be if there were no gravity. The force of gravity does not affect the horizontal component of motion; a projectile maintains a constant horizontal velocity since there are no horizontal forces acting upon it.
In a computational model of energy changes experienced by an object in free fall, the value of 9.8 appears in several of the formulas. What does this value represent ? (1 point)
Answer:
1. acceleration due to gravity
2. =$B$2-9.8*C2
3. the total energy stays the same over time
4. the total energy of the object will decrease
5. the initial potential energy will increase
Explanation:
Answer:
The person below or above me is correct use this answer.
Explanation:
My solar system has two types of planets: terrestrials and jovians. The solar nebula hypothesis offers what explanation for the different compositions of these two types of planets? A. The large gravitational forces of Jupiter tended to prevent planet formation in the inner solar system and eventually attracted most of the material into the region of the Jovian planets. B. During condensation, the heavier elements tended to sink nearer the Sun and, being rare, only provided enough material to build the relatively small terrestrial planets. C. The terrestrial planets were formed near the Sun where, because of the high temperatures, only heavier elements were able to condense. D. During the collapse of the gaseous nebula, most of the material tended to collect far from the Sun because of the large centrifugal forces, which provided the necessary material to build the large Jovian planets.
Answer:
B. During condensation, the heavier elements tended to sink nearer the Sun and, being rare, only provided enough material to build the relatively small terrestrial planets.
D. During the collapse of the gaseous nebula, most of the material tended to collect far from the Sun because of the large centrifugal forces, which provided the necessary material to build the large Jovian planets.
Explanation:
The solar nebular hypothesis is the theory of how the earth came to be as proposed and believed by most scientists. It states that the solar system was formed from a nebular which is a large collection of dust. As the condensation of the nebular progressed, the heavier materials which could withstand higher temperatures formed closer to the sun. Because these materials were not so much the planets formed by them were not large in size.
However, the Jovian planets formed beyond the frost line which could sustain icy compounds. The ices that formed these planets were much thus accounting for their larger sizes. Solar winds blew off the lighter hydrogen and helium elements leading to their accumulation far away from the sun.
Which of the following is not one of the four muscle shapes?
A. Triangular
B. Flat
C. Spindle
D. Cylindrical
Answer:
When elements bond together or when bonds of compounds are broken and form a new substance
Explanation:
where is information first stored in a human brain
Answer:
when u learn something new it goes to ur short term memory