What contributions did Johannesburg Kepler make
Answer:
Multiple
Explanation:
He was the first to determine that refraction drives vision in the eye. Using two eyes enables depth perception. Kepler is also known for defining laws regarding planetary motion.
PLZ PLZ PLZ I VOTE BRAINLY PLZPLZPLZ what is the theory of an atom created by a Dr. VAN C.
Answer: Bohr developed the Bohr model of the atom, in which he proposed that energy levels of electrons are discrete and that the electrons revolve in stable orbits around the atomic nucleus but can jump from one energy level (or orbit) to another. ... During the 1930s Bohr helped refugees from Nazism.
Drive-reduction theory states that motivation comes from a combination of both reinforcement and drive.
ОА.
True
OB. False
Which of the following is not one of the emotional expressions that are universally recognized?
OA. Happiness
OB. Disgust
OC. Sadness
OD. Love
HELPP!
Answer:
B
Explanation:
The answer should be B.
You walk 10 meters to class in 20 seconds , your average speed is ___ ?
The average speed is 1/2 m/s.
To determine the answer, we need to know about average speed.
What is average speed?Distance covered by an object per unit time is known as average speed.
What is the mathematical formula of average speed?Mathematically, average speed= Total distance travelled/ total time taken
What is the average speed, if I walk 10 metes in 20s?Here, total distance travelled = 10m,
total time taken = 20s
Average speed = 10/20 = 1/2 m/s
Thus, we can conclude that the average speed is 1/2 m/s.
Learn more about average speed here:
https://brainly.com/question/4931057
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Using the equation for Impact, can you explain the following:
Why are car steering rods designed to collapse?
Why are highway guard rails designed to crumple up on impact?
Why are traffic saftey barrels filled with water or sand?
Explanation:
Equation for Impact
FΔt = ΔP,
F = force
Δt = Impact of time
ΔP = Change in momentum
Car steering is engineered to fail in order to maximize the time of contact and hence reduce the initial impact and mitigate the damage incurred.
Road guard railing crumple on contact to maximize impact time and hence reduce impact intensity and mitigate damage.
Road safety containers are loaded with liquid or sand as they improve the period of impact.
Calculate the average speed
1) between 0 min and 3 min.
2) between 3 min and 5 min.
3) between 5 min and 10 min
4) between 0 min and 10 min
Answer:
000000000000000000000000000
Given three vectors A = 24i + 33j, B = 55i - 12j and C = 2i + 43j (a) Find the magnitude of each vector. (b) Write an expression for the vector difference A - C. (c) Find the magnitude and direction of the vector difference A-B. (d) In a vector diagram show vector A + B, and A - B, and also show that your diagram agrees qualitatively with your answer.
Answer:
(a) , . and .
(b)[tex]\vec A - \vec C=22 \hat i -10 \hat j[/tex].
(c)[tex]|\vec A - \vec B|=63.13[/tex] and the direction [tex]\theta =[/tex] 124.56°.
Explanation:
Given that,
,
and
[tex]\vec {C}=2 \hat i +43 \hat j[/tex]
(a) The magnitude of a vector is the square root of the sum of the square of all the components of the vector, i.e. for a ,.
So, the magnitude of the is
[tex]|\vec A|=\sqrt {24^2+ 33^2}[/tex]
[tex]\Rightarrow |\vec A|=\sqrt {1665}[/tex]
.
The magnitude of the is
[tex]|\vec B|=\sqrt {55^2+ (-12)^2}[/tex]
[tex]\Rightarrow |\vec B|=\sqrt {3169}[/tex]
.
And, the magnitude of the is
[tex]|\vec C|=\sqrt {2^2+ 43^2}[/tex]
[tex]\Rightarrow |\vec C|=\sqrt {1853}[/tex]
.
(b) The difference between the two vectors is the difference between the corresponding components of the vectors. So, the required expression of is
[tex]\vec A - \vec C=(24 \hat i +33 \hat j) - (2 \hat i +43 \hat j)[/tex]
[tex]\Rightarrow \vec A - \vec C=24 \hat i +33 \hat j - 2 \hat i -43 \hat j[/tex]
[tex]\Rightarrow \vec A - \vec C=22 \hat i -10 \hat j[/tex]
(c) The expression of is
[tex]\vec A - \vec N=(24 \hat i +33 \hat j) - (55 \hat i -12 \hat j)[/tex]
[tex]\Rightarrow \vec A - \vec B=24 \hat i +33 \hat j - 55\hat i +12 \hat j[/tex]
[tex]\Rightarrow \vec A - \vec B=-31 \hat i +45 \hat j\;\cdots (i)[/tex]
The magnitude of is
[tex]|\vec A - \vec B|=\sqrt {(-31)^2+55^2}[/tex]
[tex]\Rightarrow |\vec A - \vec B|=\sqrt {3986}[/tex]
[tex]\Rightarrow |\vec A - \vec B|=63.13[/tex]
Now, if a vector [tex]\vec V= -\alpha \hat i +\beta \hat j[/tex] in 3rd quadrant having direction [tex]\theta[/tex] with respect to [tex]\hat i[/tex] direction, than
in the anti-clockwise direction.
Here, from equation (i), for the vector [tex]\vec A - \vec C[/tex], [tex]\alpha=31[/tex] and [tex]\beta=45[/tex].
[tex]\Rightarrow \theta = \pi-\tan ^{-1}\left(\frac {45}{31}\right)[/tex]
180°-55.44° [as \pi radian= 180°]
124.56° in the anti-clockwise direction.
(d) Vector diagrams for [tex]\vec A +\vec B[/tex] and [tex]\vec A - \vec B[/tex] has been shown
in the figure(b) and figure(c) recpectively.
Vector [tex]\vec A - \vec B[/tex] is in 3rd quadrant as calculated in part (c).
While Vector [tex]\vec A +\vec B=(24 \hat i +33 \hat j)+(55 \hat i -12 \hat j)[/tex]
[tex]\Rightarrow \vec A +\vec B=79 \hat i +21 \hat j[/tex], which is in 1st quadrant as both the components are position has been shown in figure(b).
Why is it important not to present a biased argument as a public speaker?
A.
Because it is unconvincing
B.
Because it is immoral
C.
Because it is unfair
D.
Because it is pointless
Answer:
Explanation:
a) because it's immoral as you're trying to convince people of your views when you should be giving both sides of the story so people are able to come up with their own opinions on what you're talking about
Let's start by calculating what acceleration the rocket must produce to launch into earth orbit. In order to attain orbit around earth, the ATLAS V rocket must accelerate up to a speed of about 7700 meters per second in about 4.2 minutes. What average acceleration is required to accomplish this
Answer:
30.56 m/s^2
Explanation:
Given that In order to attain orbit around earth, the ATLAS V rocket must accelerate up to a speed of about 7700 meters per second in about 4.2 minutes.
The average acceleration that is required to accomplish this will be
Average acceleration = change in velocity / time
Average acceleration = 7700/ 4.2 × 60
Average acceleration = 7700/252
Average acceleration = 30.56 m/s^2
You are jogging with a velocity of 2 meters/second to the west, when you feel thirsty and stops to drink water after 5 seconds. First find your velocity the moment you stopped running. Then, find your acceleration during that motion. What are the units for acceleration? What is the direction of acceleration in this motion? Show your work.
Answer:
The velocity when the runner stopped is v =0 m/s
The acceleration is [tex]a = 0.4 \ m/s [/tex]
Explanation:
From the question we are told that
The initial velocity is [tex]u = 2 \ m/s[/tex]
The time taken is [tex]t = 5 \ s[/tex]
Generally from the question we are told that the person stopped running so the person velocity at that moment is v =0 m/s
Now the acceleration is mathematically represented as
[tex]a = \frac{v - u}{t}[/tex]
=> [tex]a = \frac{0 - 2}{5}[/tex]
=> [tex]a = 0.4 \ m/s [/tex]
When the sun provides energy for photosynthesis, an interaction with the __________ takes place.
A long, thin, insulated wire carries a current I1=1A out of the plane of the paper. The wire is surrounded by a long cylinder of radius a=12cm. The cylinder carries a current I2=9A that is unformly distributed over its cross section and flows into the plane of the paper.
Find the radius r at which the amgnetic field is zero.
Answer:
The magnetic field is zero at a radius r = 4 cm.
Explanation:
The magnetic field due to the wire is given by B₁ = μ₀I₁/2πr where I₁ = current in wire = 1 A and r = distance of point where magnetic field is zero from wire.
Now, since the current is uniformly distributed in the cross section of the cylinder, its current density is constant.
So, with current I₂ = 9 A flowing in the cylinder and radius, a = 12 cm. Let I' = current at radius r where the magnetic field is zero. So,
I'/πr² = I₂/πa²
I' = I₂r²/a²
Using Ampere's Law, the magnetic field B₂ at the distance r is given by
∫B.ds = μ₀I'
∫Bdscos0 = μ₀I' (since the magnetic field is parallel to the path)
B∫ds = μ₀I' ∫ds = 2πr
B2πr = μ₀I'
2Bπr = μ₀I₂r²/a²
B₂ = μ₀I₂r/2πa²
So, when the net magnetic field is zero, B₁ = B₂
So, μ₀I₁/2πr = μ₀I₂r/2πa²
I₁/r = I₂r/a²
I₁/I₂ = r²/a²
r² = I₁/I₂a²
taking square root of both sides,
r = a√(I₁/I₂)
substituting the values of the variables, we have
r = 12√(1/9)
r = 12/3
r = 4 cm
The magnetic field is zero at a radius r = 4 cm.
I need help ASAP plzzz!!!!
Answer:
1. coffee maker 2.store B. 3.yes 5. 180
Father drove 176 km in 7 hours. For the first 92 km, he spent
for 4 hours. What was his average speed for the remaining
journey?
km/h
Answer:
28km/h
Explanation:
92km = 4 hours
176 - 92 = 84
84km = 3 hours
84/3 = 28
28km/h
Hopefully this helps you :)
pls mark brainlest ;)
Help please Subject (general psychology)
Answer:
plz give the question... floor the proper answer
Explanation:
plz mark me add the brainliest
thank
me and follow ma
11. एक समान चुम्बकीय क्षेत्र में लम्बवत प्रवेश करने वाले किसी आवेशित कण द्वारा प्राप्त वृत्तीय पथ की
7 त्रिज्या का सूत्र ज्ञात कीजिए।
2
Find the formula of radius obtained by a charged particle entering perpendicularly
in a uniform magnetic field.
Answer:
r=mv/BeExplanation:
If a positive charge enters a magnetic field at 90 degrees the charge is deflected in a circular path by a force that acts perpendicular to it in line with Flemings right-hand rule
to derive the radius of the path of the charge we apply
F= mv^2/r=Bev
where
m= mass of the electronic charge
e=charge
B=magnetic field
v=average speed
r=radius
rearranging we have
r=mv^2/Bev
r=mv/Be
A pendulum is 0.760 m long, and the bob has a mass of 1,00 kg. At the bottom of its swing, the bob's speed is 1.60 m/s. The tension is greater than the weight of the bob because Multiple Choice 0 its horizontal component is increasing from zero. O the bob has a downward acceleration, so the net Fy must be downward O O the bob has zero acceleration. O ( the bob has an upward acceleration, so the net Fy must be upward Required information A pendulum is 0.760 m long, and the bob has a mass of 1.00 kg. At the bottom of its swing, the bob's speed is 1.60 m/s. What is the tension in the string at the bottom of the swing?
Answer:
T = 13.17 N
the correct one is there is a digested centripetal acceleration towards upward
Explanation:
For this exercise we can use Newton's second law at the bottom of the pendulum's path
we will assume that the upward direction is positive
T - W = m a
in this case it is describing a circle the acceleration is central
a = v² / R
where the radius of the trajectories equals the length of the pendulum
R = L
we substitute
T = mg + m v² / L
T = m (g + v² / L)
When reviewing the different statements, the correct one is there is a digested centripetal acceleration towards upward
let's calculate the tension of the rope
T = 1 (9.8 + 1.6 2 / 0.760)
T = 13.17 N
The x vector component of a displacement vector has a magnitude of 94.8 m and points along the negative x axis. The y vector component has a magnitude of 149 m and points along the negative y axis. Find (a) the magnitude and (b) direction of . Specify the direction as a positive angle with respect to the negative x axis.
Answer:
We use pythagorean theorem
So that
r = √(x² + y²)
r = √(94.8)² + (-149)² )
r =√ 9682.6 + 22201
= 178.6
direction we use
စ = tan^-1(98.4/149)
= tan^-1 (0.6604)°
What the answers due in 2 min
Hello ┬┴┬┴┤◕3◕)づ├┬┴┬┴
The answer is 3 m
the gap in between 4s and 6s is 5s
you follow your finger up to the purple like, and follow the purple line in a straight line to the left. It ends at 3m and that is your answer.
If you push a book 1.5 m across a table using a constant force of 10.0 N, how much work do you
do on the book?
Answer:
The answer is
15.0 JExplanation:
To calculate the work done by a body we use the formula
work done = force × distanceFrom the question
force = 10 N
distance covered = 1.5 m
So the work done is
work done = 10 × 1.5
We have the final answer as
15.0 JHope this helps you
Do states give up all power to withdraw when they join a union of states, or do they still retain some control over their fate?
Organized procedure to study something under controlled conditions
What is the dependent variable in this hypothesis?
After finding that objects of the same mass do not
always float or submerge the same way in a tub of
liquid, Alexis wrote a new hypothesis to test objects that
have the same mass.
o the mass of the object
O the surface area of the object
O the amount of water displaced
O the height at which the object floats
If the surface area of an object increases, then it
will float higher in the tub, because the object
would need to displace more liquid in order to sink
all the way down.
Answer:
The height at wich the object floats
Explain
took on edge 2020
Answer:
the height at which the object floats
Edge 2021
Physics Question (attached)
Answer:
The answer is "[tex]\bold{10.6 \ \ \frac{m}{s^2}}[/tex]"
Explanation:
The Formula of acceleration:
[tex]\bold{a= \frac{v-v_0}{t}}[/tex]
Given value:
[tex]t= 50\\v= 856\\v_0= 324[/tex]
Calculating the acceleration:
[tex]\to a = \frac{(856 - 324)}{50}\\\\[/tex]
[tex]= \frac{(532)}{50}\\\\= \frac{(106.4)}{10}\\\\= 10.64 \ \ \frac{ m}{s^2}[/tex]
What is the speed of an object that travels 60 meters in 4 seconds?
Answer:
15 m/s
Explanation:
s=d/t
s=60/4
s=15 m/s
Answer:
The answer would be 15 m/s
Explanation:
s=d/t
s=60/4
s= 15 m/s
Have a beautiful day beautiful
You welcome.
A sports car starts from rest at an intersection and accelerates toward the east on a straight road at 9.0 m/s2. Just as the sports car starts to move, a bus traveling east at a constant 16 m/s on the same straight road passes the sports car. When the sports car catches up with and passes the bus, how much time has elapsed
Answer:
3.6s
Explanation:
Have In mind that the sports car will catch up with bus when their positions are equal
So
S = ut + 1/2at²
where u is initial velocity
For sports car we have
x = 0 + 1/2 x 9 x t²
For Bus
S= 16ts + 0
Equating the two
1/2 x 9 x t² = 16t
4.5 x t = 16
t = 3.6s
A watermelon is dropped from the edge of the roof of a build- ing and falls to the ground. You are standing on the sidewalk and see the watermelon falling when it is 30.0 m above the ground. Then 1.50 s after you first spot it, the watermelon lands at your feet. What is the height of the building
Answer:
The hight of the building is 38.16 m
Explanation:
These two pieces of information given, first, the watermelon is 30 m above the ground and after 1.50 s the watermelon has been spotted. Now we are required to find the height of the building.
Use the below formula to find the height of buildings.
S = ut + ½ gt^2
30 =1.5u + (1/2) × 9.8 (1.5)^2
u = 12.65 m/sec
v^2 – u^2 = 2gs
(12.65)^2 = 2×9.8 s’
S’ = 8.16 m
h = s + s’
h = 30 + 8.16 = 38.16 m
The hight of the building is 38.16 m.
The height of the building is 38.16 m.
Given data:
The height above the ground is, h = 30.0 m.
The time interval after observation of first spot is, t = 1.50 s.
We need to find the height of building. And since two pieces of information given, first, the watermelon is 30 m above the ground and after 1.50 s the watermelon has been spotted. So, using the second kinematic equation of motion as,
[tex]h = ut + \dfrac{1}{2}gt^{2}[/tex]
Here, u is the initial speed. Solving as,
[tex]30 = (u \times 1.50) + \dfrac{1}{2} \times 9.8 \times (1.50)^{2}\\\\u =12.65 \;\rm m/s[/tex]
Now landing distance (s') is calculated using the third kinematic equation of motion as,
[tex]v^{2} =u^{2}+2(-g)s\\\\0^{2} =12.65^{2}+2(-9.8)s\\\\s = 8.16 \;\rm m[/tex]
Then the height of building is given as,
H = h + s
H = 30 m + 8.16 m
H = 38.16 m
Thus, we can conclude that the height of the building is 38.16 m.
Learn more about the kinematic equations of motion here:
https://brainly.com/question/16556016
A 0.091-in-diameter electrical wire at 90°F is covered by 0.02-in-thick plastic insulation (k = 0.075 Btu/h·ft·°F). The wire is exposed to a medium at 50°F, with a combined convection and radiation heat transfer coefficient of 2.5 Btu/h·ft2·°F. Calculate the critical radius (rcr) of the plastic insulation (in inches).
Answer:
The critical radius of the plastic insulation is 0.72 inches.
Explanation:
Given that,
Diameter = 0.091 in
Thickness = 0.02 in
Initial temperature = 90°F
Final temperature = 50°F
Heat transfer coefficient = 2.5 Btu/h.ft²°F
Material conductivity = 0.075 Btu/h.ft °F
We need to calculate the critical radius of the plastic insulation
Using formula of critical radius
[tex]r_{cr}=\dfrac{2K}{h}[/tex]
Where, k = Material conductivity
h = Heat transfer coefficient
Put the value into the formula
[tex]r_{cr}=\dfrac{2\times0.075}{2.5}[/tex]
[tex]r_{cr}=0.06\ ft[/tex]
[tex]r_{cr}=0.72\ inches[/tex]
Hence, The critical radius of the plastic insulation is 0.72 inches.
This ball is technology too! It can be
rolled, kicked, or thrown. Is that a need
or a want?
Answer:
want
Explanation:
people always want the new thing especially if its technology