Answer:
1. a = 9.8 m/s²
2. t = 4.28 s
3. Vf = 42 m/s
4. Vf = 28 m/s
Explanation:
1.
Since, the body is under free fall motion. Therefore, the value of its acceleration shall be equal to the acceleration due to gravity.
a = 9.8 m/s²
2.
The time taken by the ball to reach the ground can be calculated by using second equation of motion:
h = Vi t + (1/2)gt²
where,
h = height = 90 m
Vi = initial velocity = 0 m/s
t = time taken = ?
Therefore,
90 m = (0 m/s)t + (1/2)(9.8 m/s²)t²
t = √(18.36 s²)
t = 4.28 s
3.
In order to find final velocity we use first equation of motion:
Vf = Vi + gt
Vf = 0 m/s + (9.8 m/s²)(4.28 s)
Vf = 42 m/s
4.
when the ball is at height of 50 m, it means it has covered:
h = 90 m - 50 m = 40 m
we use third equation of motion at this point:
2gh = Vf² - Vi²
(2)(9.8 m/s²)(40 m) = Vf² - (0 m/s)²
Vf = √(784 m²/s²)
Vf = 28 m/s
A car drives 10km with a speed of 72 km/hr and then runs out of gas. Then you walk 2km for the next 30 min until you find a gas station. (A) What is the displacement of the total trip? (B) How long does the entire trip take? (C) What is the average velocity of the entire trip?
Answer:
A- 12 km
B- 42 minutes
C- 17.14 km per hour
Explanation:
A- The displacement of the total trip is 12 kilometers, which emerges by adding the 10 kilometers traveled by car to the 2 kilometers traveled on foot.
B- The trip, in total, took 42 minutes, which arises from adding the 30 minutes of the journey on foot, plus 12 minutes of travel by car at 72 km / h (72/60 x 10 = 12).
C- While 12 km were covered in 42 minutes, the average speed of the trip was 17.14 km / h. This arises from the following calculation:
42 = 12
60 = X
(60 x 12) / 42 = X
17.14 = X
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
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.
65°F to degrees Celsius
Answer:
18.3 C
Explanation:
Answer: 55/3 °C
Explanation:
Formula:
C=5/9(F-32)
Given:
F=65
Solve:
C=5/9(F-32)
C=5/9(65-32)
C=5/9(33)
C=55/3
If you walk 5 km north and then 12 km east. Your resultant displacement is____.a. magnitude: 1.1km; direction: 53.1 degrees east of north.b. magnitude: 2.00; direction: 53.1 degrees east of north.c. magnitude: 2.00; direction: 36.9 degrees east of north.d. magnitude: 1.1km; direction: 36.9 degrees east of north.
Answer:
Resultant = 13km
Direction = 67.38° East of North
Explanation:
Given the following :
5km North ; 12km East
Resultant Displacement (r) :
r² = 5² + 12²
r² = 25 + 144
r² = 169
r = √169
r = 13
Direction:
Tangent = opposite / Adjacent
Tanθ = opposite / Adjacent
Opposite = 12 ; adjacent = 5
Tanθ = (12/5)
Tanθ = 2.4
θ = tan^-1(2.4)
θ = 67.38° east of north
When the sun provides energy for photosynthesis, an interaction with the __________ takes place.
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:
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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
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.
Suppose a radio signal (light) travels from Earth and through space at a speed of 3 × 108/ (this is the speed of light in vacuum). How far (in meters) into space did the signal travel during the first 10 minutes?
Answer:
18*10^10 meters
Explanation:
V= d/t 10 mins = 600 seconds
3*10^8 = d/600s
(3*10^8)*(6*10^2) = d
d = 18*10^10 m
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
An object, initially at rest, moves 250 m in 17 s. What is its acceleration?
Answer:
1.73 m/s²
Explanation:
Given:
Δx = 250 m
v₀ = 0 m/s
t = 17 s
Find: a
Δx = v₀ t + ½ at²
250 m = (0 m/s) (17 s) + ½ a (17 s)²
a = 1.73 m/s²
The acceleration of this object is 1.730 meter per seconds square.
Given the following data:
Initial velocity = 2.5 m/s (since the object is starting from rest).Time = 17 seconds.To find the acceleration of this object, we would use the second equation of motion.
Mathematically, the second equation of motion is given by the formula;
[tex]S = ut + \frac{1}{2} at^2[/tex]
Where:
S is the displacement or distance covered.u is the initial velocity.a is the acceleration.t is the time measured in seconds.Substituting the given values into the formula, we have;
[tex]250 = 0(17) + \frac{1}{2} (a)(17^2)\\\\250 = \frac{1}{2} (289)a\\\\250 = 144.5a\\\\a = \frac{250}{144.5}[/tex]
Acceleration, a = 1.730 [tex]m/s^2[/tex]
Therefore, the acceleration of this object is 1.730 meter per seconds square.
Read more: https://brainly.com/question/7998145
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.
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 ;)
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
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
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]
If an automobile with a velocity of 4.0 m/s accelerates at a rate of 4.0 m/s2
for 2.5 s, what is the final velocity?
Answer:
V=u+at
=4+4*2.5
=14m/s
Explanation:
Initial velocity =4m/s
acceleration =4m/(second) squared
time =2.5 seconds
v=u+at
v=4+4*2.5
v=14m/s
27.
In a graph showing how temperature of a material changes over time, temperature
change is the:
A. dependent variable
C. variable with the smallest range
B. independent variable
D. variable with the largest range
Answer:
A. Dependent variable
Explanation:
In a graph showing how temperature of a material changes over time, temperature is taken on y-axis and time is taken on x-axis. It shows how temerature altered as the time changes.
In temperature-time graph, temperature is directly dependent on time. With the increase in time, temperature rises, falls or remains constant. It implies that temperature is dependent variable that depend on time.
Hence, the correct option is (A).
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).
A stone is thrown vertically downward with an initial speed of 12.0 m/s from the top of a
building. The stone takes 1.54 s to reach the ground.
The question is incomplete; However, the height from which the stone is thrown is most likely to be what's required of the question
Answer:
See Explanation
Explanation:
Given
[tex]Initial\ Speed, u = 12.0m/s[/tex]
[tex]Time, t = 1.54\ s[/tex]
Required
Determine the height
This question will be answered using the following equation of motion;
[tex]S = ut + \frac{1}{2}gt^2[/tex]
Take g as 9.8
This gives:
[tex]S = 12 * 1.54 + \frac{1}{2} * 9.8 * 1.54^2[/tex]
[tex]S = 12 * 1.54 + \frac{1}{2} * 9.8 * 2.3716[/tex]
[tex]S = 18.48 + 11.62084[/tex]
[tex]S = 30.10084[/tex]
[tex]S = 30.1\ m[/tex] (Approximated)
Hence; Height = 30.1m
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
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)°
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:
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Two cylindrical resistors are made from the same material. The shorter one has a length LL and diameter DD . The longer one has a length 16L16L and diameter 4D4D . How do their resistances compare? The resistance of the longer resistor is four times the resistance of the shorter resistor. The resistance of the longer resistor is twice the resistance of the shorter resistor. The resistance of the longer resistor is the same as the resistance of the shorter resistor. The resistance of the longer resistor is half the resistance of the shorter resistor. The resistance of the longer resistor is a quarter of the resistance of the shorter resistor.
Answer:
The resistance of the longer resistor is a quarter of the resistance of the shorter resistor.Explanation:
If Two cylindrical resistors are made from the same material, then their resistivity will be the same. Formula for calculating resistivity of a material is expressed as;
[tex]\rho = \frac{RA}{L} \ where \ A = \frac{\pi d^2}{4}[/tex] where;
R is the resistance
A is the cross sectional area of the material
L is the length of the material
For the shorter cylinder:
Length = L
diameter = D
[tex]\rho = \dfrac{R_s(\frac{\pi D^2}{4})}{L} \\\\\rho = \dfrac{R_s{\pi D^2}}{4L}[/tex]
For the longer cylinder:
Length = 16L
diameter = 4D
[tex]\rho = \dfrac{R_l(\frac{\pi (4D)^2}{4})}{16L} \\\\\\\rho = \dfrac{R_l(\frac{\pi (16D^2)}{4})}{16L} \\\\\rho = \dfrac{R_l{16\pi D^2}}{16L}\\\\\rho = \dfrac{R_l{\pi D^2}}{L}[/tex]
Since their resistivity are the same then;
[tex]\dfrac{R_s{\pi D^2}}{4L} = \dfrac{R_l{\pi D^2}}{L} \\\\ \dfrac{R_s}{4} = {R_l} \\\\R_s = 4R_l\\\\R_l = \frac{R_s}{4}[/tex]
Hence the resistance of the longer resistor is a quarter of the shorter resistor.
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.
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
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]
(b) If you decrease the length of the pendulum by 25%, how does the new period TN compare to the old period T?
Answer:
The new period will be reduced by 50%
Explanation:
The period of pendulum is given by;
[tex]T= 2\pi\sqrt{\frac{L}{g} }\\\\\frac{T}{2\pi} = \sqrt{\frac{L}{g} }\\\\(\frac{T}{2\pi} )^2 = {\frac{L}{g}}\\\\\frac{T^2}{4\pi ^2} = {\frac{L}{g}}\\\\T^2(\frac{g}{4\pi ^2}) = L\\\\ \frac{g}{4\pi ^2}= \frac{L}{T^2}\\\\\frac{L_1}{T_1^2} = \frac{L_2}{T_2^2}[/tex]
When the length is decreased by 25%, the new length L₂ is given by;
L₂ = 25/100(L₁)
L₂ = 0.25L₁
[tex]\frac{L_1}{T_1^2} = \frac{L_2}{T_2^2}\\\\T_2^2 = \frac{T_1^2L_2}{L_1} \\\\T_N^2 = \frac{T^2(0.25L_1)}{L_1}\\\\ T_N^2 =0.25T^2\\\\T_N = \sqrt{0.25T^2}}\\\\T_N = 0.5 T[/tex]
Thus, the new period will be reduced by 50%