Answer:
(a) The height of the cliff is 9.92 m
(b) Time taken to reach the ground is 0.81 s
Explanation:
Given;
time of motion of the rock, t = 2.48 s
initial velocity of the rock, u = 8.19 m/s
(a) This is a two-way problem;
maximum upward height reached by the rock (h) + Total distance traveled downwards from the top (H).
Height of cliff = H - h
Maximum height reached by the rock;
[tex]v^2 = u^2 - 2gh\\\\0 = (8.19)^2 - (2\times 9.8)h\\\\0 = 67.08 - 19.6 h\\\\19.6h = 67.08\\\\h = \frac{67.08}{19.6} \\\\h = 3.422 \ m[/tex]
Time to reach the maximum height;
[tex]h = ut - \frac{1}{2} gt^2\\\\3.422 = 8.19t - (0.5 \times 9.8)t^2\\\\3.422 = 8.19t - 4.9t^2\\\\4.9t^2 -8.19t + 3.422 = 0\\\\This \ forms \ a quadratic \ equation ; \\\\a = 4.9, b = -8.19, c = 3.422\\\\t = \frac{-b \ \ +/- \ \ \sqrt{b^2 -4ac} }{2a} \\\\t = \frac{-(-8.19) \ \ +/- \ \ \sqrt{(-8.19)^2 -4(4.9\times 3.422)} }{2(4.9)} \\\\t = \frac{8.19 \ \ + /- \ \ \sqrt{0.0049} }{9.8} \\\\t = \frac{8.19 - 0.07}{9.8} \ \ or \ \ t = \frac{8.19 + 0.07}{9.8} \\\\t = 0.83 \ s \ \ or \ \ t = 0.84 \ s\\\\[/tex]
The time taken for rock to falll to the gound;
t₂ = 2.48 - 0.83 s
t₂ = 1.65 s
The distance traveled downwards is calculated as
H = vt + ¹/₂gt²
where;
v is the final velocity at maximum height = initial velocity when the rock starts moving downwards = 0
H = ¹/₂gt²
H = 0.5 x 9.8 x (1.65)²
H = 13.34 m
The height of the cliff = 13.34 m - 3.422m = 9.92 m
(b) time taken to reach the ground if thrown with the same speed;
h = ut + ¹/₂gt²
9.92 = 8.19t + (0.5 x 9.8)t²
9.92 = 8.19t + 4.9t²
4.9t² + 8.19t - 9.92 = 0
a = 4.9, b = 8.19, c = -9.92
use the quadratic formula;
[tex]t = \frac{-b \ \ +/- \ \ \sqrt{b^2 -4ac} }{2a} \\\\t = \frac{-8.19 \ \ +/- \ \ \sqrt{(8.19)^2 -4(4.9\times -9.92)} }{2(4.9)} \\\\t = 0.81 \ s[/tex]
You’re working with a patient who suddenly falls. You should?
C.
A palm fruit dropped to the ground from the top of
a tree 45m tall. How long does it take to reach the
ground? A. 9s B. 4.5s C. 6 D. 7.5s E. 35
(g = 10ms2).
Answer:
b 4.5
Explanation:
time=distance/speed
3. Sally (45 kg) and Stan (90 kg) and arrive at Michigan Adventure and climb the stairs to ride the big
Shivering Timber coaster that is nearly 40 m tall and reaches speeds of 65 mi/hr.
a) Compare the potential energies of Sally and Stan as they wait in line at the top of the stairs.
Explain your reasoning.
If you move 10 times farther away from a source of light, then how will the
apparent brightness of that source change?
it will become 10 times less bright
it will become 2 times less bright
its brightness will not change
O it will become 100 times less bright
Andrea, a 61.5 kg sprinter, starts a race with an acceleration of 3.700 m/s2. If she accelerates at that rate for 12.00 m and then maintains that velocity for the remainder of a 100.00 m dash, what will her time (in s) be for the race
Answer:
The total time it will take her to complete the race is 13.17 s
Explanation:
Given;
mass of the sprinter, m = 61.5 kg
acceleration of the sprinter, a = 3.7 m/s²
first distance covered, d₁ = 12 m
Determine her velocity for the first 12 m;
v² = u² + 2as
v² = 0 + (2 x 3.7 x 12)
v² = 88.8
v = √88.8
v = 9.42 m/s
Determine her time for the first 12 m;
v = u + at
9.42 = 0 + 3.7t₁
9.42 = 3.7t₁
t₁ = 9.42 / 3.7
t₁ = 2.55 s
Determine the time it will take her to complete the last 100 m at a constant velocity of 9.42 m/s
s = vt₂ + ¹/₂at₂²
s = vt₂ + ¹/₂(0)t₂²
s = vt₂
100 = 9.42t₂
t₂ = 100 / 9.42
t₂ = 10.62 s
The total time it will take her to complete the race = 2.55 s + 10.62 s
= 13.17 s
A force (5ỉ - ;)N moves an object from the point P (1,3) m to the point Q (3, 8) m.
The work (in )) done by the force is
Select one:
a. -10
O b.5
o c.-13
d. 8
Answer:
b) 5 J
Explanation:
Work is the energy transferred by an object when acted by a force along a displacement. Work is the product of force and displacement. The SI unit of work is the joules (J)
To calculate the work done by the force, we have to first get the displacement (D) of the object. Hence:
Displacement (D) = Q(3, 8) - P(1, 3) = (3 - 1, 8 - 3) = (2, 5) = 2i + 5j
The work done is the dot product of the force and the displacement. Force = 5i - j. Hence:
Work done = (5i - j)(2i + 5j) = 10 - 5 = 5 J
PLS HELP ME. A 0.0780 kg lemming runs off a 5.36m high cliff at 4.84 m/s what is it potential energy when it lands?
Answer:
p.e=0.078kg×1/2×5.36m
p.e=0.913j
Which of the following is the best definition of a physical change?
A. A change in a substance where a new substance is formed
B. A change in a substance in which bonds are broken
C. A change in a substance with no new substances being formed
D. A change in a substance in which mass is conserved
Answer:
The answer is C. A change in a substance with no new substances being formed
Explanation:
I did the quiz.
The best definition of physical change is a change in a substance, with no new substances being formed. Hence, option C is correct.
What is a Physical Change?A chemical substance's form, not its chemical composition, can change due to physical changes. In most cases, compounds cannot be separated into chemical components or simpler compounds; instead, mixtures are separated into their constituent compounds through physical changes.
Whenever something changes physically but not chemically, we say that something has changed physically. This is in contrast to the idea of a chemical change, which occurs when a substance's composition changes or when one or more compounds join or fragment to generate new substances. In general, physical means can be employed to undo a physical alteration. For instance, by letting the water evaporate, salt that has been dissolved in it can be reclaimed.
Therefore, this concludes that option C is correct.
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The human eye has two lenses.
O true
O False
Answer:
true its truedjjs sjsnsns
The cliff divers at Acapulco, Mexico, jump off a cliff m above the ocean. Ignoring air resistance, how fast are the divers going when they hit the water
Answer:
22.87 m/s
Explanation:
Since the value of the height at which the divers jump off the cliff is not given,
Assuming that the height of the cliff above the ocean at which the divers jump = 26.7 m
Then;
The speed of the divers when they hit the ocean water can be determined by using the formula:
[tex]v^2 = 2gh \\ \\ v= \sqrt{2gh} \\ \\ v = \sqrt{2 \times 9.8 \times (26.7)} \\ \\ v \simeq 22.87 \ m /s[/tex]
Two cars travel in the same direction along a straight highway, one at a constant speed of 55 mi/h and the other at 60 mi/h.How far must the faster car travel before it has a 15-min lead on the slower car
Answer:
The distance traveled by the faster car when it is 15 mins ahead of the slower car is 165 miles.
Explanation:
Given;
speed of the faster car, v₁ = 60 mi/h
speed of the slower car, v₂ = 55 mi/h
Let the distance traveled by the faster car when it is 15 mins ahead of the slower car = x miles
[tex]\frac{x}{55} - \frac{x}{60} = \frac{15}{60}[/tex]
Note: divide 15 mins by 60 to convert to hours for consistency in the units.
[tex]\frac{x}{55} - \frac{x}{60} = \frac{15}{60}\\\\multiple \ through \ by \ 660\\\\12x - 11x = 165\\\\x = 165 \ miles[/tex]
Therefore, the distance traveled by the faster car when it is 15 mins ahead of the slower car is 165 miles.
Answer this
a) which ink is likely to be pure? Why?
b) What does the chromatography tell us about ink Y
c) Why are the three different spots separated out from ink Y found at different heights?
Answer:
a) Ink X is likely to be pure because it only contain 1 spot.
b) The chromatography tell us about ink Y that it is a mixture as it contain more than 1 spot.
c) The three different spots are separated out from ink Y at different heights beacaus different substance have different solubility.
The different spots from Y are found at various heights because they represent different compounds.
What is chromatography?The term chromatography has to do with a method of separating the component of a substance. The term chromatography originally means color writing.
We can see that the pure ink is the ink marked X. We can see from the chromatogram that Y is a mixture of colors. The different spots from Y are found at various heights because they represent different compounds.
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Wave 1
WWW
m
Resulting
Wave
Wave 2
Wave 2 Phase Shift
The resulting wave has the largest possible amplitude when Wave-1 and Wave-2 are exactly in step ... their peaks both happen at the same time and their troughs both happen at the same time.
This means that Wave-1 and Wave-2 have the same frequency, and the phase shift from one wave to the other is zero.
When all of that happens, the amplitude of the resulting wave is the sum of the amplitudes of Wave-1 and Wave-2. If Wave-1 and Wave-2 have the same amplitude, then the resulting wave will have double that amplitude.
PLEASE HELPPPPPP!!!!!!
Explanation:
Since gravitational forces are inversely proportional to the square of their distances, tripling the distance means the reduction of the force by a factor of 9. That means the force experienced by the two objects will be 1/9 smaller than before.
Many adventures like to go rafting on the Colorado River through Grand Canyon National Park. There are many locations where the river becomes more narrow, both the distance between the canyon walls as well as the depth changes due to debris like boulders on the bottom of the river; this leads to changes in the water speed. In the park, the Colorado River has an average width of 100m and an average depth of 8m, and an average speed of 3 m/s. At the Lava Falls Rapids, the river has an average width of about 25m and an average depth of about 15m. What is the approximate speed of the water in this location
Answer:
6.4 m/s
Explanation:
Given that :
The average width of the Colorado river = 100 m
Average depth of the river is = 8 m
Therefore, area = [tex]$A_1= 100 \ m \times 8 \ m$[/tex]
Speed of the river, [tex]$v_1 = 3 \ m/s$[/tex]
After the lava falls on the river,
Width of the river becomes = 25 m
Depth of the river became = 15 m
Therefore, area = [tex]$A_2= 25 \ m \times 15 \ m$[/tex]
Now, since the volume flow rate of the Colorado river is same, then from the Continuity equation,
[tex]$Q_1=Q_2$[/tex]
[tex]$A_1v_1=A_2v_2$[/tex]
∴ [tex]$100 \times 8 \times3 = 25 \times 15 \times v_2$[/tex]
[tex]$v_2=\frac{100 \times 8 \times 3}{25 \times 15}$[/tex]
= 6.4 m/s
Therefore, the speed of the river in this location is 6.4 m/s
Dos cargas puntuales iguales y negativas, q1=q2=-24micro C se localizan en x=0 y y=38m y x=0 y y=-7m, respectivamente. Calcula la magnitud de la fuerza electrica total en N que ejercen estas dos cargas sobre una tercera, tambien puntual, Q=26micro C en y=0 y x=16m
Answer:
F_net = 9.87 10⁻⁴ N
Explanation:
Let's use that force is a vector magnitude
∑ F = F₁₃ + F₂₃
De bold arfe vectros. The force is the electric force, we use that charges of the same sign repel and when the charges are of a different sign they attract
the charges q1 and q2 are negative and the charge q3 is positive with the positions y1 = 38 m, y2 = -7m, y3 = 16 m
∑ F = F₁₃ - F₂₃
F_net = [tex]k \frac{q_1q_3}{r_{13}^2 } - k \frac{q_2q_3}{r_{23}^2 }[/tex]
in this case q₁ = q₂ = q
F_net = k q q₃ ( )
let's look for the distance
r₂₃ = y₂ - y₃
r₂₃ = -7 -16
r₂₃ = - 23 m
r₁₃ = 38 - 16
r₁₃ = 22 m
let's calculate
F_net = 9 10⁹ 24 26 10⁻¹² ( )
F_net = 5.616 ( 1.758 10⁻⁴ )
F_net = 9.87 10⁻⁴ N
Each of the four expansion models (recollapsing, critical, coasting, and accelerating) predict different ages for the universe, given the current expansion rate. Why is this
Answer:
This is because the age of the universe is determined by the pace of expansion in the past, and each model forecasts a different pace.
Explanation:
The age of the universe is determined by the pace of expansion in the past, and each model forecasts a different pace.
This is due to the fact that the expansion rate in the coasting model is constant and never changes. Because the cosmos is growing faster now than during the old days, recollapsing and critical models give shorter ages. According to the accelerating model, the universe is growing at a slower rate currently than in the past, implying an older age.
A voltage of 75 V is placed across a 150 Ω resistor. What is the current through the resistor?
Answer:
0.5 A
Explanation:
Applying,
V = IR.................. Equation 1
Where V = Voltage, I = current, R = Resistance.
make I the subject of the equation
I = V/R............... Equation 2
From the question,
Given: V = 75 V, R = 150 Ω
Substitute these values into equation 2
I = 75/150
I = 0.5 A.
Hence the cuurent through the resistor is 0.5 A
I need an answer ASAP this is Mass Times acceleration
Answer:
[tex]force = mass \times acceleration \\ 1200 = 400 \times a \\ a = \frac{1200}{400} \\ a = 3 \: {ms}^{ - 2} [/tex]
If two dogs are pulling a bone with force-20Newtons in opposite direction, then the resultant force is
Answer:
Newtons third law of motion: Balanced forces
Every action has a corresponding and opposing response, according to Newton's third law of motion. As a result, forces always work in pairs. Once more, tug-of-war is a prime illustration.
What force in opposite direction follow newton law?The third law of motion by Newton states that equal, but diametrically opposed forces always act in pairs. There is an equal but opposite reaction to every action, to put it another way.
The forces are balanced if the pullers are exerting equal force but going in the opposite direction on either side of the rope. There is hence no motion.
Although equal and opposite in nature, action and reaction forces cannot be balanced since they act on separate things and do not cancel one another out.
Therefore, This means that when you push against a wall, the wall pushes back against you with an equal amount of force.
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A camera lens used for taking close-up photographs has a focal length of 22.0 mm. The farthest it can be placed from the film is 32.9 mm. What is the closest object that can be photographed
Answer:
p = 6.64 cm
Explanation:
For this exercise we use the equation of the constructor
[tex]\frac{1}{f} = \frac{1}{p} + \frac{1}{q}[/tex]
where f is the focal length, p and q are the distance to the object and the image, respectively
They tell us the focal length f = 2.2 cm and that the image as far as it can go is q = 3.29 cm, let's find the position of the object that creates this image
[tex]\frac{1}{p} = \frac{1}{f} - \frac{1}{q}[/tex]
1 / p = 1 / 2.2 - 1/3.29
1 / p = 0.15059
p = 6.64 cm
therefore the farthest distance from the object is 6.64 c
Heellppppppppppp!!!!
Answer:
B, the internet serves to provide people with more insightful explanations on things that they have not experienced yet but want to find out more on.
please help! will mark brainliest
Answer:
27.D.28.AExplanation:
THE ANSWERME MY ANSWERWAH IS ME AND MY ANSWER WAHHHWALA NA SIYA WALA NA SIYA MASAYA MASAYA MASAYA WAHHtinapon na siya tipon na siya wahhsa basurahan wahh wahh ...............____ is the study of things getting faster as they move.
A. Anatomy
B. Force
C. Physics
D. Dynamics
Answer: b force
Explanation:
yes because the world comin g up with more technique
By how many newtons does the weight of a 85.9-kg person lose when he goes from sea level to an altitude of 6.33 km if we neglect the earth's rotational effects
Answer:
[tex]Weight\ loss=1.6321N[/tex]
Explanation:
From the question we are told that:
Weight [tex]W=85.9kg[/tex]
Altitude [tex]h= 6.33 km[/tex]
Let
Radius of Earth [tex]r=6380km[/tex]
Gravity [tex]g=9.8m/s^2[/tex]
Generally the equation for Gravity at altitude is mathematically given by
[tex]g_s=9.8(\frac{6380}{6380+6.33})^2[/tex]
[tex]g_s=9.781m/s^2[/tex]
Therefore
Weight at sea level
[tex]W_s=9.8*85.9[/tex]
[tex]W_s=841.82N[/tex]
Weight at 6.33 altitude
[tex]W_a=9.781*85.9[/tex]
[tex]W_a=840.2N[/tex]
Therefore
[tex]Weight loss=W_s-W_b[/tex]
[tex]Weight loss=841.82-840.2[/tex]
[tex]Weight loss=1.6321N[/tex]
A 4.9 A current is set up in a circuit for 4.7 min by a rechargeable battery with a 12 V emf. By how much is the chemical energy of the battery reduced
Answer:
E = 16581.6 J
Explanation:
Given that,
Current, I = 4.9 A
Time for which the current is set up, I = 4.7 min = 282 s
The voltage of the battery, V = 12 V
We need to find how much chemical energy of the battery reduced. Let It is E. We know that,
E = P t
Where
P is power of battery, P = VI
So,
[tex]E=VIt[/tex]
Put all the values,
[tex]E=12\times 4.9\times 282\\E=16581.6\ J[/tex]
So, 16581.6 J of chemical energy of the battery is reduced.
One coulomb represents how many electrons?
a. 1 electron
b. 100 electrons
C. 6.25 quintillion electrons
d. 6.25 million-million electrons
e, none of the above
Answer:
6.24 x 1018 electrons.
Explanation:
So I think C
The index of refraction of n-propyl alcohol is 1.39. Find the angle of refraction of light in that medium if light comes from air with an angle of incidence of 55 degrees.
Answer:
36.11 degrees
Explanation:
index of refraction n = sin i/sinr
i is the angle of incidence
r is the angle of refraction
Substitute into the expression
1.39 = sin55/sin(r)
1.39 = 0.8191/sin(r)
sin(r) = 0.8191/1.39
sin(r) = 0.5893
r = arcsin(0.5893)
r = 36.11
hence the angle of refraction of light is 36.11 degrees
Besides toxic pollution, the other types of pollution are sediment pollution, nutrient pollution, and bacterial pollution.
a. True
b. False
Answer:
a. True
Explanation:
Pollution can be defined as the physical degradation or contamination of the environment through an emission of harmful, poisonous and toxic chemical substances.
Aside from toxic pollution, the other types of pollution includes the following;
I. Sediment pollution.
II. Nutrient pollution.
III. Bacterial pollution.
Furthermore, particulate pollution is a form of pollution that is responsible for the degradation of the environment.
Particulate matter is also referred to as particle pollution or atmospheric aerosol particles and it can be defined as a complex microscopic mixture of liquid droplets and solid particles that are suspended in air. Other forms of particle pollution includes space debris and marine debris.
Some examples of particulate pollution are dusts, soot, dirt, smoke, etc.
Answer:a
Explanation:
If a spider can travel 3.5 meters in 25 minutes, how fast can they go?