A boy throws rocks with an initial velocity of 12m/s [down] from a 20 m bridge into a river. Consider the river to be at a height of 0 m. Draw a velocity-time and position-time graph. Use up as position and ignore air resistance.
Answers
Answer:
Please find attached the Velocity-Time graph, the Displacement-Time graph and the combined Velocity/Displacement-Time graph, created with Microsoft Excel
Explanation:
The given parameters are;
The initial velocity with which the boy throws the rock, u = 12 m/s
The direction in which he throws the rock = Down
The height from which the rock was thrown, h = 20 m
The height at which the river is located = 0 m
The kinematic equation of motion, of the rock can be given as follows;
h = u·t + 1/2·g·t²
Where;
t = The time of motion of the rock
g = The acceleration due to gravity = 9.8 m/s²
h = The height from which the rock is thrown = 20 m
Substituting the known values into given equation, we get;
20 = 12·t + 1/2·9.8·t² = 12·t + 4.9·t²
4.9·t² + 12·t - 20 = 0
t = (-12 ± √(12² - 4×4.9×(-20)))/(2 × 4.9) = (-12 ± √(242))/(9.8)
t ≈ -3.587 seconds or t ≈ 1.138 seconds
Attached please find the Velocity-Time graph, the Displacement-Time graph and the combined Velocity/Displacement-Time graph, created with Microsoft Excel.
![A Boy Throws Rocks With An Initial Velocity Of 12m/s [down] From A 20 M Bridge Into A River. Consider](https://brainimage.s3.us-east-005.backblazeb2.com/answers/attachments/jhzk8X7ssOlmX35aeCFPX5nppyixhPfM.jpeg)
![A Boy Throws Rocks With An Initial Velocity Of 12m/s [down] From A 20 M Bridge Into A River. Consider](https://brainimage.s3.us-east-005.backblazeb2.com/answers/attachments/9wbfty2O91cmWvnw46DdZ0ahz9rC6jnP.jpeg)
![A Boy Throws Rocks With An Initial Velocity Of 12m/s [down] From A 20 M Bridge Into A River. Consider](https://brainimage.s3.us-east-005.backblazeb2.com/answers/attachments/hIk2JQvpaeNJlqQlvV7cIfymNEzFNALa.jpeg)
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Answers
Answer:
9394 NExplanation:
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force = mass × acceleration
From the question we have
force = 4697 × 2
We have the final answer as
9394 NHope this helps you
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Answers
Answer:
83.3m
Explanation:
From the question we are given the following:
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Answers
Answer:
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Explanation:
HELP?
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Answer:
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hope it helps you
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Answers
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Answer:
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Answer:
All cave animals and organisms fit into three categories. Placement into these categories depends on how much time the organisms actually spend in the cave.
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-Crayfish (sometimes)
Troglobites are animals that live in the cave but do not come out. They often have physical adaptions to the cave life like no vision, or loss pigment because light does not reach this part of the cave. Examples would be
-Snails that have thin white shells and small eyes
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-Bats
-Bears
-Skunks
-Raccoon
-Moths (sometimes)
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-Beetles
-Worms
-Frogs
-Salamanders
-Crickets
-Spiders
-Crayfish (sometimes)
Troglobites are animals that live in the cave but do not come out. They often have physical adaptions to the cave life like no vision, or loss of pigment because light does not reach this part of the cave. Examples would be
-Snails that have thin white shells and small eyes
-Blind cavefish which has no eyes and no color
-Kauai Cave Wolf Spider which also has no eyes.
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C.The ends of the magnets repel each other but the centers attract. D.One magnet is storing energy & one magnet is releasing energy.
Answers
Answer:
A. like poles repel or push apart
What is the net work done to lift a 6 kg block a height of 5.3 meters and then lower it back to the ground where it started?
Answers
Answer:
636 J
Explanation:
The weight of the block is =mg = 6kg × 10 ms-2 = 60 N
Since it was raised and dropped back to it's original position, distance = 5.3 × 2 = 10.6 m
Work done = 60N × 10.6 m = 636 J
Draw a ray diagram to show the formation of an image when the object is placed beyond the ‘c’of a concave mirror.
Answers
the object is real inverted and diminishes
Examine the following equation.
10n+23592U→310n+9236Kr+14156Ba+energy
0
1
n
+
92
235
U
→
3
0
1
n
+
36
92
K
r
+
56
141
B
a
+
e
n
e
r
g
y
Which type of nuclear reaction does the equation represent?
A)nuclear fusion
B)nuclear decay
C)radiation
D)nuclear fission
Answers
Answer:
E)brain decay
Explanation:
Looking at the question causes it.
Answer: D
Explanation: because
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concert is 75 miles away, and you make it there in and two hours. What was the average
speed?
Answers
Answer:
37.5
Explanation:
divide
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How many degrees above the ground is the sloth compared to its initial position?
Answers
Answer:
The answer is 53.13
Explanation:
Cuz it is. It's not that hard
Answer:
A sloth moves 3 M to the right and then climbs 4 m up a tree.
How many degrees above the ground is the sloth compared to its initial position?
Answer: 53.1°
Attached here is the question:
Answers
Answer:
t = 6 [s]
Explanation:
In order to solve this problem we must first use this equation of kinematics.
[tex]v_{f}^{2}=v_{o}^{2} +2*a*x[/tex]
where:
Vf = final velocity = 0 (the car comes to rest)
Vo = initial velocity = 72 [km/h]
a = acceleration [m/s²]
x = distance = 60 [m]
First we must convert the velocity from kilometers per hour to meters per second.
[tex]72 [\frac{km}{h}]*\frac{1000m}{1km} *\frac{1h}{3600s} =20 [m/s][/tex]
[tex]0=(20)^{2} -2*a*60\\400 = 120*a\\a=3.33[m/s^{2} ][/tex]
Now using this other equation of kinematics.
[tex]v_{f}=v_{o}-a*t[/tex]
0 = 20-3.33*t
t = 6[s]
The brakes on a 15,680 N car exert a stopping force of 640 N.
The car's velocity changes from 20.0 m/s to 0 m/s. What is the
mass of the car? (Estimate 10 N/kg for g.)
Answers
Answer:
1568 Kg is the answer
Explanation:
What is vertical motion
Answers
the movement of an object in a straight line. When an object is thrown up, it always comes down, this is due to gravity