Answer:
they were hunter gatherers
Explanation:
sample of pure boron contains only isotope X and isotope Y.
A nucleus of X has more mass than a nucleus of Y.
[o[4].[4] The sample is ionised, producing ions each with a charge of +1.6 x 10°C.
The specific charge of an ion of X is 8.7 x 10°C kg".
Calculate the mass of an ton of X.
[1 mark]
h
mass of ion = kg
[4].[2] Determine the number of nucleons in a nucleus of X.
mass of a nucleon = 1.7 x 1077 kg
[2 marks]
h
number of nucleons =
[o[4].[3] Compare the nuclear compositions of X and Y.
[2 marks]
[o[4].[4] lons of Y have the same charge as ions of X.
State and explain how the specific charge of an ion of X compares with that of an
ion of Y.
[2 marks]
Answer:
[tex]1.84[/tex]×[tex]10^{-26}[/tex]
Explanation:
specific charge = [tex]\frac{charge}{mass}[/tex] so by rearranging for mass we get
mass= [tex]\frac{charge}{sepcifc charge}[/tex]
[tex]\frac{1.6×10^{-26} }{1.7×10^{-27} }[/tex] = answer in kg
what must be the mass of a rock if a boy applies a 64N force and causes it to accelerate at 4.51m/s2
first of all the formula of force is F=ma,so we are searching for m,so we can divide a on both sides F/a=m, after this substitute the values given above 64N/4.51=14.2°Kg
What do you mean by physics?
Answer:
Explanation:
Physics is the branch of science that studies the natural world and its rules and orders. It is one of the oldest sciences as ancient people study the stars and astronomy is considered part of Physics.
Which of the following is NOT part of the grain group?
Answer:
Any food made from wheat, rice, oats, cornmeal, barley, or another cereal grain is a grain product. Anything else is not
Explanation:
sound wave of a wave length of 0.56 meters if its speed is 280 m/s what is the wave frequency
Answer:
500 Hz
Explanation:
Formula for finding wave frequency is,
f = c/λ
f = frequency
c = speed (m/s)
λ = wave length (m)
f = c/λ
f = 280/0.56
f = 500
∴ wave frequency is 500 Hz
What is the index of refraction of a refractive medium if the angle of incidence in air is 40 degrees and the angle of refraction is 29 degrees?
The index of refraction is 1.33.
To find the answer, we need to know about index of refraction.
What is index of refraction?
The indication of the light bending ability of a medium is the refractive index of that medium.It determines how much the path of light is bent or refracted.It's a dimensionless number.What is the mathematical expression of refractive index?
Mathematically, the refractive index(n) isn= sin∅₁ / sin∅₂
where, ∅₁= angle of incident
∅₂= angle of refraction
What is the refractive index, if the angle of incidence in air is 40 degrees and the angle of refraction is 29 degrees?
n= sin(40) /sin(24) = 1.33Thus, we can conclude that the index of refraction is 1.33.
Learn more about refractive index here:
https://brainly.com/question/83184
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What my fav food for 20 points if you know it!?
Answer:
pizza
Explanation:
Answer:
sea food???
Explanation:
Coherent light with wavelength of 580 nm passes through two very narrow slits, and the interference pattern is observed on a screen a distance of 3.00 m from the slits. The first-order bright fringe is at 4.81 mm from the center of the central bright fringe. For what wavelength of light will the first-order dark fringe be observed at this same point on the screen?
Answer:
the required wavelength is 1.15815 μm
Explanation:
Given the data in the question;
The position of bright fringes [tex]y_m[/tex] on screen in double slit experiment is expressed as follows;
[tex]y_m[/tex] = mλD / d
solving for d, we substitute 1 for m
y₁ = (1)λD / d
d = λD / y₁
given that λ = 580 nm = 5.8 × 10⁻⁷ m, D = 3.00 m and y₁= y₀ = 4.81 mm = 0.00481 m
so we substitute
d = λD / y₁
d = ( 5.8 × 10⁻⁷ m × 3.00 m ) / 0.00481 m
d = 0.00000174 m² / 0.00481 m
d = 3.6117 × 10⁻⁴ m
Now, position of dark fringe [tex]y_m[/tex] on screen in double slit experiment is expressed as;
[tex]y_m[/tex] = ( m + 1/2 )λD / d
we substitute 0 for m
y₀ = ( 0 + 1/2 )λD / d
y₀ = λD / 2d
2y₀d = λD
λ = 2y₀d / D
we substitute
λ = ( 2(0.00481 m) ( 3.6117 × 10⁻⁴ m) ) / 3.0 m
λ = 1.15815 × 10⁻⁶ m
λ = 1.15815 μm
Therefore, the required wavelength is 1.15815 μm
What is a gravitational force?
Answer:
It is the force that pulls down an object on the air
Answer: a downward pull on any object
Explanation:
Suppose we replace both hover pucks with pucks that are the same size as the originals but twice as massive. Otherwise, we keep the experiment the same. Compared to the pucks in the video, this pair of pucks will rotate View Available Hint(s) Suppose we replace both hover pucks with pucks that are the same size as the originals but twice as massive. Otherwise, we keep the experiment the same. Compared to the pucks in the video, this pair of pucks will rotate four times as fast. at the same rate. one-fourth as fast. twice as fast. one-half as fast.
Answer:
w = w₀ / 2 the angular velocity is half the initial value.
Explanation:
We can analyze this exercise as if we added another disk to obtain a disk with twice the mass, for which if the system is two disks, the angular tidal wave is conserved
initial instant.
L₀ = I₀ w₀
final moment
L_f = I w
the moment is preserved
L₀ = L_f
I₀ w₀ = I w
the moment of inertia of a disk is
I = ½ m R²
we substitute
½ m R² w₀ = ½ (2m) R² w
w = w₀ / 2
for the case of a disk with twice the mass, the angular velocity is half the initial value.
PLEASE HELP! I'LL GIVE BRAINLEST
Answer:
Weight = 8.162 Newton.
Explanation:
Given the following data;
Mass = 2.2 kg
Acceleration due to gravity = 3.71 N/kg
To find the weight of the textbook;
Weight = mass * acceleration due to gravity
Weight = 2.2 * 3.71
Weight = 8.162 N
Therefore, the weight of the science textbook in mars is 8.162 Newton.
Two identical speakers are set some distance apart in a large open field. Both are producing sound, in unison, with a wavelength of 4 m. An observer wandering around the field notices that the sound is surprisingly loud at certain locations and unusually quiet at others. The observer concludes that this is the effect of interference between the two sources of sound waves. For each location, indicate which sort of interference would occur at that point.
Answer:
Constructive interference occurs at the surprisingly loud locations and destructive interference occurs at the unusually quiet locations.
Explanation:
This is because, constructive interference tends to combine the effects of the wave when they are in phase (that is, moving in the same direction), which thus amplifies the effect and produces surprisingly loud sounds at those locations, while destructive interference occurs when the waves are out of phase with each other(that is, move in opposite directions) and thus, their effects tend to cancel out thus producing locations of unusually quiet sounds.
A 0.545-kg ball is hung vertically from a spring. The spring stretches by 3.56 cm from its natural length when the ball is hanging at equilibrium. A child comes along and pulls the ball down an additional 5cm, then lets go. How long (in seconds) will it take the ball to swing up and down exactly 4 times, making 4 complete oscillations before again hitting its lowest position
Answer:
t = 9.52 s
Explanation:
This is an oscillatory motion exercise, in which the angular velocity is
w = [tex]\sqrt{ \frac{k}{m} }[/tex]
Let's use hooke's law to find the spring constant, let's write the equilibrium equation
F_e - W = 0
F_e = W
k x = m g
k = [tex]\frac{m g}{x}[/tex]
k = 0.545 9.8 /0.0356
k = 150 N / m
now the angular velocity is related to the period
W = 2π / T
we substitute
4π² T² = k /m
T = 4pi² [tex]\sqrt{ \frac{m}{k} }[/tex]
we substitute
T = 4 pi² [tex]\sqrt{ \frac{0.545}{150} }[/tex]
T = 2.38 s
therefore for the spring to oscillate 4 complete periods the time is
t = 4 T
t = 4 2.38
t = 9.52 s
Which is true regarding a child standing up for their own rights?
Answer:
hey mate......looks like the question is incomplete
A student wearing in-line skates pushes against a brick wall. why does the student move away from the wall ?
1. Because the forces acting on the student are balanced
2. Because the forces acting on the student are creating a net force
3. Because gravity is less than the student's push on the wall
4. Because the friction between the skates and the pavement is greater than the student's push on the wall
Answer:
Because the forces acting on the student are creating a net force.
Explanation:
I took the test and that was the answer
Answer:
Because the forces acting on the student are creating a net force
Explanation:
What are 5 examples of steong forces and what are 5 examples of weak forces. Thx!
Answer: The Strong Nuclear Force is an attractive force between protons and neutrons that keep the nucleus together and the Weak Nuclear Force is responsible for the radioactive decay of certain nuclei.
Explanation:
Half Time At 3:00 the hour hand and the minute hand of a clock point in directions that are 90.0
apart. What is the first time after 3:00 that the angle between the two hands has decreased by half to 45.0?
The first time after 3:00 that the angle between the two hands has decreased by half to 45.0 is 3:08:11.
Angular velocity of the hour hand
The angular velocity of the hour hand for 12 hours time is calculated as follows;
[tex]\omega_h = \frac{2\pi}{12(3600 \ s)}[/tex]
Angular velocity of the minute handThe angular velocity of the minute hand for 12 hours time is calculated as follows;
[tex]\omega _m = \frac{2\pi}{3600}[/tex]
Difference in the angular velocity[tex]\Delta \omega = \frac{2\pi }{3600} - \frac{2\pi }{12(3600)} = \frac{11(2\pi)}{12(3600)} = \frac{22\pi}{12 (3600)}[/tex]
First angle between the two hands in radians[tex]45^0 = \frac{45}{180} \pi= \frac{\pi}{4}[/tex]
Time after 3:00The time after 3:00 is calculated as follows;
[tex]t =( \frac{\pi}{4}) /\frac{22\pi}{12(3600)} \\\\t = \frac{\pi }{4} \times \frac{12(3600)}{22\pi} \\\\t = 490.91 \ s\\\\t = 8 \min, \ 10.91 \ s[/tex]
[tex]t \approx 8\min, 11 \ s[/tex]
Thus, the first time after 3:00 that the angle between the two hands has decreased by half to 45.0 is 3:08:11.
Learn more time in angular difference here: https://brainly.com/question/7815
A light bulb has a resistance of 360 . What is the current in the bulb when it has a potential difference of 120 V across it? 0.33 A 3 A 480 A 43,200 A
Answer:
I=R×V
360×120 V
=43,200 A
Answer:
A.)0.33 A
Explanation:
i just took the quiz 2021
Please help & actually answer thank you :)
Answer:
0.5x35=17.5
Explanation:
You throw 0.5 kg the ball leaves your hand with
A speed of 35
Scroll over the answer choices to see the images. Choose all of the true statements concerning the corresponding image
The picture depicts an electric motor which turns electrical energy into mechanical energy.
The picture depicts a generator which turns electrical energy into mechanical energy
A series circuit is a good example of an electromagnet
F more wite is wound around this iron mail, the strength of the electromagnetic is increased
This image devices that the direction of the magnetic field does not depend on the direction of the current
Flow of electron |
Answer:
Explanation:
I jus did it on usatestprep
i Lapalli using Newtonian laws.
c) (i) A trailer loaded with 500 bags of cement
(ii) A racing car
(iii) A motor bike. Which of these three has the lowest inertia? Why?
Answer:
(iii) A motor bike.
Explanation:
Inertia can be defined as the tendency of an object or a body to continue in its state of motion or remain at rest unless acted upon by an external force.
In physics, Sir Isaac Newton's first law of motion is known as law of inertia and it states that, an object or a physical body in motion will continue in its state of motion at continuous velocity (the same speed and direction) or, if at rest, will remain at rest unless acted upon by an external force.
The inertia of an object such as a trailer is greatly dependent or influenced by its mass; the higher quantity of matter in a trailer, the greater will be its tendency to continuously remain at rest. Also, this is applicable to all physical objects.
Hence, a motor bike would have the lowest inertia because it has the least amount of mass among the other physical objects given in this scenario.
PLEASE HELP ME WITH THIS ONE QUESTION
A piston has a volume change of 7 x 10^-6 m^3. Assuming atmospheric pressure is 101,325 J, what is the work needed to change the piston volume?
Correct question:
A piston has a volume change of 7 x 10^-6 m^3. Assuming atmospheric pressure is 101,325 Pa, what is the work needed to change the piston volume?
Answer:
The work needed to change the piston volume is 0.709 J
Explanation:
Given;
volume of the piston, V = 7 x 10⁻⁶ m³
atmospheric pressure, P = 101,325 Pa
The work needed to change the piston volume is calculated as follows;
W = PV
W = (7 x 10⁻⁶ m³) x (101,325 Pa)
W = 0.709 J
Therefore, the work needed to change the piston volume is 0.709 J
Brian Lara is a cricketer playing in the field on the second day of a cricket test-match. He exerts a forward force on the 0.145kg cricket ball, as he catches it, to bring it to rest from a speed of 38.2m/s. During the process, his hand recoils a distance of 0.135m. Determine the acceleration of the ball and the force which is applied to it by Brian Lara.
Answer:
a = -3984.6 m/s²
F = 577.76 N
Explanation:
The acceleration of the ball can be calculated by using the third equation of motion:
[tex]2as = v_f^2 - v_i^2\\[/tex]
where,
a = acceleration of ball = ?
s = distance covered = recoil distance = 0.135 m
vf = final speed = 0 m/s
vi = initial speed = 38.2 m/s
Therefore,
[tex]2(0.135\ m)a = (0\ m/s)^2-(38.2\ m/s)^2\\[/tex]
a = -3984.6 m/s²
here negative sign shows deceleration.
Now, for the force applied by Brian Lara will be equal in magnitude but opposite in direction of the force required to stop the ball:
[tex]F = -ma\\F = -(0.145\ kg)(-3984.6\ m/s^2)\\[/tex]
F = 577.76 N
A researcher would like to perform an experiment in a zero magnetic field, which means that the field of the earth must be canceled. Suppose the experiment is done inside a solenoid of diameter 1.0 m, length 4.6 m , with a total of 5000 turns of wire. The solenoid is oriented to produce a field that opposes and exactly cancels the 52 μT local value of the earth's field.
What current is needed in the solenoid's wires?
Express your answer to two significant figures and include the appropriate units.
Answer:
I = 3.81 x 10⁴ A
Explanation:
The magnetic field of a solenoid must be equal to the field of earth:
[tex]Field\ of\ Earth = Field\ of\ Solenoid\\52\ T = \mu n I\\I = \frac{52}{\mu n}[/tex]
where,
I = current passing through solenoid = ?
μ = permeability of free space = 4π x 10⁻⁷ N/A²
n = no. of turns per unit length = [tex]\frac{5000\ turns}{4.6\ m}[/tex] = 1086.96 /m
Therefore,
[tex]I = \frac{52\ T}{(4\pi\ x\ 10^{-7}\ N/A^2)(1086.96\ /m)}[/tex]
I = 3.81 x 10⁴ A
what happens during subduction
Answer:
Subduction , Latin for "carried under," is a term used for a specific type of plate interaction. It happens when one lithospheric plate meets another—that is, in convergent zones —and the denser plate sinks down into the mantle.
3.
Two Cars, A and B, (starting, at the same time, from the same point) are moving
with average speeds of 40 km/h and 50 km/h, respectively, in the same direction.
Find how far will Car B be from Car A after 3 hours.
Answer:
car B will be 30 Km ahead of car A.
Explanation:
We'll begin by calculating the distance travelled by each car. This is illustrated below:
For car A:
Speed = 40 km/h
Time = 3 hours
Distance =?
Speed = distance / time
40 = distance / 3
Cross multiply
Distance = 40 × 3
Distance = 120 Km
For car B:
Speed = 50 km/h
Time = 3 hours
Distance =?
Speed = distance / time
50 = distance / 3
Cross multiply
Distance = 50 × 3
Distance = 150 Km
Finally, we shall determine the distance between car B an car A. This can be obtained as follow:
Distance travelled by car B (D₆) = 150 Km
Distance travelled by car A (Dₐ) = 120 Km
Distance apart =?
Distance apart = D₆ – Dₐ
Distance apart = 150 – 120
Distance apart = 30 Km
Therefore, car B will be 30 Km ahead of car A.
Which of the following is NOT a natural
source of pollution?
A. erupting volcanoes
B. dust storms
C. construction
D. forest fires
Answer:
hi
Explanation:
answer is C
have a nice day
PLEASE HELPPPPPP!ASAPPPPPPP
Answer:
Altitude is the height of landmass calculated from sea level. No it has no effect on weight.
Explanation:
The altitude at sea level is always assumed to be 0°, thus as you move away from altidude is calculated in increments while moving into the sea, the vice versa is true.
This force will cause the path of the particle to curve. Therefore, at a later time, the direction of the force will ____________. This force will cause the path of the particle to curve. Therefore, at a later time, the direction of the force will ____________. have a component along the direction of motion remain perpendicular to the direction of motion have a component against the direction of motion first have a component along the direction of motion; then against it; then along it; etc.
Answer:
have a component along the direction of motion that remains perpendicular to the direction of motion
Explanation:
In this exercise you are asked to enter which sentence is correct, let's start by writing Newton's second law.
circular movement
F = m a
a = v² / r
F = m v²/R
where the force is perpendicular to the velocity, all the force is used to change the direction of the velocity
in linear motion
F = m a
where the force is parallel to the acceleration of the body, the total force is used to change the modulus of the velocity
the correct answer is: have a component along the direction of motion that remains perpendicular to the direction of motion
PLEASE HELP and actually help plz
The position of masses 4kg, 6kg, 7kg, 10kg ,and 3kg are (0,1), (4,2), (3,5), (5,6), and (-2,4) respectively. Where must you place a mass of 13kg if you want the center of mass to be at (-1,-3)?
Answer:
iEvaluate for \(x=2.\)Evaluate for \(x=2.\)Evaluate for \(x=2.\)Evaluate for \(x=2.\)Evaluate for \(x=2.\)Evaluate for \(x=2.\)Evaluate for \(x=2.\)
Explanation:
