A skateboarder, starting from the top of a ramp 4,5 m above the ground, skates down the ramp. The mass of the skateboarder and his board is 65 kg
Use the principle of conservation of mechanical energy to calculate the magnitude of the velocity of the skateboarder when he reaches the ground
Answers
Answer:
Kinetic Energy at bottom=2886.5J (when g=9.8m/s²)
OR
2925J (if g=10m/s²)
Answer:
Explanation:
The potential energy (PE) of the skateborder (and board) is given by mgh (mass, gravity acceleration, and height). Assuming no friction of any kind, the magnitude of the skateboarder's velocity will be the result of converting the potential energy to kenetic energy (KE), (1/2)mv².
[We only know the magnitude of the velocity since we aren't told in which direction the skateboarder is headed.]
1. Calculate PE:
mgh
(65kg)*(9.61m/s²)*(4.5m) = 2811 kgm²/s² (Joules)
2. Calculate Speed from KE
Since we are assuming no friction nor other forces, all of the PE will be converted to KE, so we can write:
PE = (1/2)mv²
2811 kgm²/s² = (1/2)*(65kg)v²
v² = (2811 kgm²/s²)/((1/2)*(65kg))
v² = 86.49 m²/s²
v = 9.3 m/s : The magnitude of the velocity.
===================
I vote pointing the skateboarder west, where the gold is. His velocity would be 9.3 m/s West.
Related Questions
calculate the mass fo an unknown solid if its density is 1.6 g/cm^3 and it has a length of 7.5 cm, a height of 12.5 cm, and a width of 2.2 cm
Answers
Answer:
Density = Mass / Volume
Mass = Density * volume = 1.6 gm/cm^3 * (7.5 * 12.5 * 2.2) cm^3
Mass = 1.6 gm/cm^3 * (206 cm^3) = 330 gm
2. Why do you think a light stick would be a good light source around flammable material?
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Answer:
because it doesnt contain fire
an unbalanced force of 965 N causes an object to accelerate at 54.5 m/s^2. what is the mass of the object
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Answer:
[tex]F=ma \\ 965 = m(54.5) \\ m = \frac{965}{54.5} \\ m = 17.7kg[/tex]
6. A squirrel performs 20 J of work climbing a tree in 5 seconds. What
was the squirrel's power?
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a wave is recalling with a speed of 5m/s for 7 seconds. How far has the wave travelled?
Answers
Answer:
35m
Explanation:
Take the speed of 5m/s and multiply that by 7 seconds. You get 35m
2. Elements in a family have the same
A. total number of electrons
B. protons and neutrons
C. number of valence electrons
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Answer:
Elements in a family have the same
Ans C. number of valence electrons
A plane is flying through the sky at a constant speed. The thrust of the aeroplane (making it go forwards) is 100N. Air resistance is also acting on the plane. What must the resultant (overall) force be on the plane?
A: 0N
B: 50N
C: 100N
D: 150N
Answers
Answer: 0N
Explanation: Hope this helps :)
last time i wrote the wrong answer for the wrong problem :)
For the constant speed, the resultant force on the plane is 0N. So, the correct option is A.
What is Force?A force is defined as the parameter that can change the momentum of an object that can cause an object with mass to change its velocity, i.e., to accelerate. Force can also be described intuitively as a push or pull where force has both magnitude and direction, making it a vector quantity.
For above given information, the plane is moving at a constant speed. According to Newton's first law, the net external force on the aircraft due to the thrust generated by the propeller must be zero and air resistance is equal and in opposite directions to produce zero net force.
Thus, for the constant speed, the resultant force on the plane is 0N. So, the correct option is A.
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You place a small sphere with a net charge of 5 space x space 10 to the power of negative 6 end exponent space C at one corner of a square that measures 5 m on each side. What is the magnitude of the electric field at the opposite corner of the square?
900 N/C
9,000 N/C
450 N/C
4,500 N/C
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(Sorry if this didn’t help)
which gravitational pull has the greatest effect on tides?
Answers
Answer: The pull of the Moon's gravity on Earth is the primarily cause of tides and the pull of the Sun's gravity on Earth is the secondary cause. The Moon has a greater effect because, although it is much smaller than the Sun, it is much closer. The Moon's pull is about twice that of the Sun's.
why is the cooling system in a nuclear power station important? what will happen if the system malfunction?
Answers
Cooling Power Plants
The amount of cooling required by any steam-cycle power plant (of a given size) is determined by its thermal efficiency. It has essentially nothing to do with whether it is fuelled by coal, gas or uranium.
However, currently operating nuclear plants often do have slightly lower thermal efficiency than coal counterparts of similar age, and coal plants discharge some waste heat with combustion gases, whereas nuclear plants rely on water.
Nuclear power plants have greater flexibility in location than coal-fired plants due to fuel logistics, giving them more potential for their siting to be determined by cooling considerations.
The most common types of nuclear power plants use water for cooling in two ways:
To convey heat from the reactor core to the steam turbines.
To remove and dump surplus heat from this steam circuit. (In any steam/ Rankine cycle plant such as present-day coal and nuclear plants there is a loss of about two-thirds of the energy due to the intrinsic limitations of turning heat into mechanical energy.)
Mechanical waves form when a source of energy causes a medium to what
Answers
Answer:
Ripple in water is a surface wave. A mechanical wave is a wave that is an oscillation of matter, and therefore transfers energy through a medium. While waves can move over long distances, the movement of the medium of transmission —the material—is limited.
Find a unit vector perpendicular to the vectors given A=4i+2j+2k and B=4i-4j+8k.
Answers
The cross product of A and B is perpendicular to both A and B.
A × B = (4i + 2j + 2k) × (4i - 4j + 8k)
A × B = 16 (i × i) - 16 (i × j) + 32 (i × k) + 8 (j × i) - 8 (j × j) + 16 (j × k) + 8 (k × i) - 8 (k × j) + 16 (k × k)
A × B = -16 (i × j) - 32 (k × i) - 8 (i × j) + 16 (j × k) + 8 (k × i) + 8 (j × k)
A × B = -16k - 32j - 8k + 16i + 8j + 8i
A × B = 24i - 24j - 24k
The magnitude of A × B is
||A × B|| = 24 ||i - j - k|| = 24√3
Dividing A × B by its magnitude gives a unit vector,
(A × B)/||A × B|| = 1/√3 (i - j - k)
an amusement park ride has two identical carriages that revolve around the center of the ride’s axle, as shown in the figure. both carts travel at a constant tangential speed at all points along the circular path. at what position is the total mechanical energy of the cart-cart-earth system at its maximum value?
Answers
The principle of conservation of energy allows to find the result for the mechanical energy of the system is:
Mechanical energy is conserved at all points, therefore at all points it has the same value.
Mechanical energy is defined by the sum of the kinetic energy and the potential energies.
Em = K + U
In the principle of energy conservation, it establishes that energy cannot be created or destroyed, it is only transformed, in the case of no friction, mechanized energy is conserved at all points.
They indicate that the system is rotating, which is why it is subjected to a force that expends its energy in changing the direction of the speed to keep the system in rotation, so the speed of the system remains constant.
Em = K = ½ I w²
Consequently, using the principle of conservation of energy we can find the result for the mechanical energy of the system is:
Mechanical energy is conserved at all points, therefore at all points it has the same value.
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. A small toy car having 300 grams of mass and going straight with an initial velocity of 13 m/s. When the toy car collides with an obstacle, a resistive force of 4 N acts upon it. The speed of the toy car reduced and reached 8 m/s. Draw its free body diagram and then find the time for the toy car to be into rest position?
Answers
The free-body diagram is attached in the image below. The time for the toy car to be in rest position is 0.6 s
From the given information:
The mass of the toy car = 300 g = 0.3 kgThe initial velocity (u) of the car = 13 m/sThe resistive force F_r acting on the car = 4 NThe speed of the car (v) = 8 m/sA force is regarded as a push that causes an alteration in motion of an object within a specified distance. It is usually expressed by the formula:
Force = mass × acceleration∴
acceleration = Force/massacceleration = (4 / 0.3) m/s²acceleration = 13.33 m/s²Using the first equation of motion for the time to bring the car to rest from it reduced speed of 8 m/s;
v' = v + atsince the final speed to bring the car in rest position is (0), then:
0 = 8 - 13.33(t)
13.33(t) = 8
t = 8/13.33
t = 0.6 seconds
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The transfer of the minerals of the earth to living organisms and then back to the earth again is called a:
cycle
niche
community
chain
Answers
A cycle is a series of changes that are continuously repeated, where each part understandably relates to other parts.
ANSWER MADE BY AN AI
Answer: cycle
Explanation:
A 1 kg cart has 5 J of work done on it. If the initial velocity of the cart was 3 m/s, what is the final velocity of the cart?
A.5.6
B.3.1
C.3.73
D.4.4J
Answers
Answer:
D: 4.4m/s
Explanation:
From a known theorem the total work on a body is equal of the variation of kinetic energy:
[tex]W = \Delta K = K_f-K_i = \frac12 mv_f^2 - \frac12 m v_i^2[/tex]
Taking the first and last step in the chain of equalities and replacing the values we have, we get:
[tex]5 = \frac12(1)v_f^2 - \frac12(1)(3)^2\\10= v_f^2 -9 \rightarrow v_f^2 = 19 \rightarrow v_f=\sqrt19 \approx 4.4m/s[/tex]
the amount of force applied per given area is
Answers
Answer:
Explanation: The amount of force applied per given area is pressure...(F/A)
SI unit=Pascals(Newtons/m^2)
7. Sally's mass on Earth is 50 kg. What is her weight on the moon?
The acceleration due to gravity she experiences on the moon is 1.652
a. 490 N
b. 8.3 kg
c. 50 kg
d. 82.6 N
Answers
Answer:
82.6
Explanation:
3 points
A science teacher is going to make a Newton's Cradle using students on
swings. *
A
B C
Which of the following statements is true?
Answers
Answer:
When a ball on one end of the cradle is pulled away from the others and then released, it strikes the next ball in the cradle, which remains.
So it will be D
Explanation: Hope this helps :)
write a relations between wavelength frequency and velocity for a sound wave
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Answer:
[tex]{ \boxed{ \mathfrak{answer : \: { \rm{v = f \lambda}}}}}[/tex]
Explanation:
v is the velocityf is frequencylambda is wavelength[tex]{ \underline{ \mathfrak{ \green{Good \: grace}} \: \:⚜ \: \: { \blue{ \mathfrak{Good \: God}}}}}[/tex]
How are particles in liquids, solids, and gases the same? How are they different?
Answers
Answer:
Gases, liquids and solids are all made up of atoms, molecules, and/or ions, but the behaviors of these particles differ in the three phases. ... gas are well separated with no regular arrangement. liquid are close together with no regular arrangement. solid are tightly packed, usually in a regular pattern.
Explanation:
#CARRYONLEARNING
What are the 4 classes of Platyhelmintheses and how are they different.
Answers
Answer: Platyhelminthes are divided into four classes: Turbellaria, free-living marine species; Monogenea, ectoparasites of fish; Trematoda, internal parasites of humans and other species; and Cestoda (tapeworms), which are internal parasites of many vertebrates.Mar 5, 2021
Explanation:
I need help! Use your observations to support or reject this claim "If the samples are at the same temperature, the amount of thermal energy in a sample depends on the type of material and the amount of the material" Its the Phet Lab
Answers
Answer:
i cannot see the the claim
Explanation:
An object has an acceleration of 18.0 m/s/s. If the net force
was tripled and the mass were halved, then the new
acceleration would be m/s/s.
Answers
Answer:
Explanation:
F = ma
net force equals mass times acceleration
lets put some test variables just to experiment.
36 = 2 (18)
now do what the question says
108 = 1 (a)
acceleration would be 108 meters per second squared
A roller is pushed with a force of 100 N along its handle, which is at an angle of 60 degrees with the horizontal. Find the work done in moving it through 20 m?
Answers
Answer:
1 kJ
Explanation:
By definition of work, [tex]W = \vec F \cdot \vec x = |\vec F| |\vec x| cos\angle Fx[/tex]. Let's replace the values: [tex]W = 100N\cdot 20m \cdot cos 60 = 1000 J[/tex]
What do all waves carry
Answers
Answer:
Light, heat, radio, and similar types of energy
can you give me brainliest
Explanation:
Light, heat, radio, and similar types of energy are carried by a variety of waves in the ELECTROMAGNETIC SPECTRUM. Some energy waves need a medium, such as water or air, through which to travel.
Determine the force required to move a block if the coefficient of static friction of one block and the floor is 0.35 and the coefficient of the static friction between 2 boxes is 0.25
Answers
Answer:
32.5
Explanation:
Choose the normal force acting between the object and the ground. Let's assume a normal force of 250 N .
Determine the friction coefficient. ...
Multiply these values by each other: (250 N) * 0.13 = 32.5 N .
You just found the force of friction!
in general, what happens to the density and temperature of a gas as it expands?
Answers
The temperature of a gas will increase and the density will decrease as it
expands.
The expansion of gas happens as a result of an increase in the elastic
collision of the atoms. This is as a result of the increase in temperature which causes the atoms to be more spatially arranged.
The density of gas also reduces as a result of the same number of gas
molecules occupying more volume.
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Watch the video and make a ninja star. Once you have made a ninja star, 5 Point Ninja Star. Explain the energy transfer in the ninja star once it has been assembled.
PLEASE HELP
Answers
Answer:
kinetic energy because it is movement
Explanation:
Data Set B: help plz
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Answer: hey buddy their is no image for me sorry man
Explanation:
