Answer:
d = 120 [m]
Explanation:
In order to solve this problem, we must use the theorem of work and energy conservation. Where the energy in the final state (when the skater stops) is equal to the sum of the mechanical energy in the initial state plus the work done on the skater in the initial state.
The mechanical energy is equal to the sum of the potential energy plus the kinetic energy. As the track is horizontal there is no unevenness, in this way, there is no potential energy.
E₁ + W₁₋₂ = E₂
where:
E₁ = mechanical energy in the initial state [J] (units of Joules)
W₁₋₂ = work done between the states 1 and 2 [J]
E₂ = mechanical energy in the final state = 0
E₁ = Ek = kinetic energy [J]
E₁ = 0.5*m*v²
where:
m = mass = 60 [kg]
v = initial velocity = 12 [m/s]
Now, the work done is given by the product of the friction force by the distance. In this case, the work is negative because the friction force is acting in opposite direction to the movement of the skater.
W₁₋₂ = -f*d
where:
f = friction force = 36 [N]
d = distance [m]
Now we have:
0.5*m*v² - (f*d) = 0
0.5*60*(12)² - (36*d) = 0
4320 = 36*d
d = 120 [m]
I need help asappp!!! Help b trcrcrhhvvcc
Answer:
the answer is c. hope this help you out
Which object might have the pattern of magnetic domains shown in the
image?
114 114
114 114
11 11
A. Cotton fabric near a magnet
O B. A piece of iron, not near a magnet
O C. A piece of iron near a magnet
D. Cotton fabric, not near a magnet
Answer: a piece of iron near a magnet
Explanation:
A car speeds up from 0.00 m/s to 60.0
m/s in 8.53 s.
The acceleration of the car is:
A. 512 m/s2
B. 8.53 m/s2
C. 68.5 m/s2
D. 7.03 m/s2
change the following to celisus
a.-400f b.800f
please its urgent i will give u brainliest
what do electrons move from
Answer:
Negatively charged, to positively charged parts
Explanation:
Electrons are negative, negative is attracted to positive.
Why do we use insulators if they prevent the flow of electricity?
Answer:
letterman is shooting the kids
We use insulators to avoid being electrocuted. electricians use rubber gloves to avoid shock. Cables are insolated with rubber so you can hold them without getting shocked even if it is plugged in.
What is the form of energy that our eyes can detect?
A. Sound Energy
B. Chemical Energy
C. Light Energy
D. Thermal Energy
Answer: C. Light energy.
Explanation:
A car accelerates from 20 m/s to 80 m/s in 5 seconds. What is the
average acceleration of the car?
a 20 m/s2
b 12 m/s2
C 4 m/
d 16 m/s2
Answer:
12m/s2
Explanation:
:D (just a smiley, not answer d)
A 56 kg diver runs and dives from the edge of a cliff into the water which is located 4.0 m below. If she is moving at 8.0 m/s the instant she leaves the cliff, determine the following.
Her gravitational potential energy relative to the water surface when she leaves the cliff
Her kinetic energy when she leaves the cliff
Her total mechanical energy relative to the water surface when she leaves the cliff
Her total mechanical energy relative to the water surface just before she enters the water.
The speed at which she enters the water.
Answer:
1) 2197.44 J
2) 0 J
3) 2197.44 J = Constant
4) 2197.44 J
5) Approximately 8.86 m/s
Explanation:
The given parameters are;
The mass of the diver, m = 56 kg
The height of the cliff, h = 4.0 m
The speed with which the diver is moving, vₓ = 8.0 m/s
The gravitational potential energy = Mass, m × Height of the cliff, h × Acceleration due to gravity, g
1) Her gravitational potential energy = 56 × 4.0 × 9.81 = 2197.44 J
2) The kinetic energy = 1/2·m·u²
Where;
u = Her initial velocity = 0 when she just leaves the cliff
Therefore;
Her kinetic energy when she just leaves the cliff = 1/2 × 56 × 0² = 0 J
3) The total mechanical energy = Kinetic energy + Potential energy
The total mechanical energy is constant
Her total mechanical energy relative to the water surface when she leaves the cliff = Her gravitational potential energy = 2197.44 J = Constant
4) Her total mechanical energy relative to the water surface just before she enters the water = 2197.44 J
5) The speed with which she enters the water, v, is given from, v² = u² + 2·g·h
Where;
u = The initial velocity at the top of the cliff before she jumps= 0 m/s
∴ v² = 0² + 2 × 9.81 × 4 = 78.48
v = √78.48 ≈ 8.86 m/s
The speed with which she enters the water, v ≈ 8.86 m/s
1) Her gravitational potential energy relative to the water surface when she leaves the cliff is; GPE(leaves cliff) = 2195.2 J
2) Her kinetic energy when she leaves the cliff is; KE = 0J
3) Her total mechanical energy relative to the water surface when she leaves the cliff is; ME_total = 2195.2 J
4) Her total mechanical energy relative to the water surface just before she enters the water is; ME_total = 2195.2 J
5) The speed at which she enters the water is; v = 8.85 m/s
We are given;
Mass of the diver; m = 56 kg
Height of the cliff; h = 4 m
Speed at which she is moving; vₓ = 8 m/s
1) Formula for gravitational potential energy is;
GPE = mgh
where;
m is mass
g is acceleration due to gravity
h is height
Thus;
GPE = 56 × 4 × 9.8
GPE(leaves cliff) = 2195.2 J
2) The formula for kinetic energy when she leaves the cliff is;
KE = ¹/₂mu²
Where;
m is mass
u = initial velocity = 0 m/s
Thus;
KE = ¹/₂ × 56 × 0²
KE(leaves cliff) = 0 J
3) The total mechanical energy relative to the water surface when she leaves the cliffis;
ME_total = GPE(leaves cliff) + KE(leaves cliff)
Thus;
ME_total = 2195.2 + 0
ME_total = 2195.2 J
4) Her total mechanical energy relative to the water surface just before she enters the water is same as that when she leaves the cliff = 2195.2 J
5) The speed with which she enters the water, v, is gotten from newtons third equation of motion;
v² = u² + 2gh
Thus;
v² = 0² + (2 × 9.8 × 4)
v² = 78.4
v = √78.4
v = 8.85 m/s
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pls help me i’m begging u
Answer:
C
Explanation:
Balanced forces cancel each other out so they do not change the object's motion
A student wishes to conduct an investigation on heat transfer that demonstrates convection, Which
method should the student use?
A.
Pour hot, colored water into a bowl of cooler water that is another color,
B.
Melt chocolate bars in a microwave at different settings,
C.
Leave a glass of ice water outside in the direct sunshine.
D.
Place a spoon that is room temperature on top of a hot burner on a stove,
a supersonic aircraft travels faster than the speed of sound. What might be the top speed of such an aircraft? 200 Kilometers per hour 500 Kilometers per hour O 1000 Kilometers per hour O 1500 Kilometers per hour
1500 kpm
How does Health & Physical Education relate to any other subject you now study in
school?
Answer:
Health relates to science because
in science you study, research, and knowledge in this case, health science, which helps you under stand more about how humans and animals function. And Physical education relates to science because , you study the way of human movement, think of push-ups as a example.
I hope I helped U ´꓃ ` U
A subway car moves at a constant speed of 10 m/s over a period of 10 s. What is the instantaneous speed halfway through this motion
Answer: 10 m/s
We're told the speed is constant, so it's not changing throughout the time period given to us. So throughout the entire interval, the speed is 10 m/s.
What is the Range of the projectile motion?
Answer:
Range of projectile, R
For projection above ground surface, the range of the angle of projection with respect to horizontal direction, θ, is 0° ≤ θ ≤ 90° and the corresponding range of 2θ is 0° ≤ 2θ ≤ 180°.S
hope you're looking for this.
6. A total of 135 J of work is done on a gaseous refrigerant as it undergoes compression. If
the internal energy of the gas increases by 114 J during the process, what is the total amount
of energy transferred as heat? Has energy been added to or removed from the refrigerant as
heat?
Answer:
Eh = 21 [J]
Removed as heat.
Explanation:
This is a case of energy conservation, we have to take into account the energies that go in and out of the system. In this case, 135 [J] of energy are entered in the form of work of the compressor to the chamber where the refrigerant is compressed, now of these 135 [J] 114 [J] were used as internal energy, this internal energy is used to increase the pressure and temperature of the refrigerant.
In this way the rest of the energy of the 135 [J] was lost in the form of heat to determine this loss of energy, we simply perform the arithmetic subtraction.
Eh = 135 - 114 = 21 [J]
Eh = 21 [J]
What does it mean for objects to be at different temperatures?
which change to a circuit is most likely to increase it electrical power
A: increase it's current and increase it's voltage
B: decrease it's current and increase it's voltage
C: decrease it's current and decrease it's voltage
D: increase it's current and decrease it's voltage
Answer:
A................
Explanation:
Hope this helps you
A. increase it's current and increase it's voltage
Explanation:
What is Latin word for "little lumps?"
Answer:
tura paulo
Explanation:
sry if im wrong ;)
Finding the area of a trapezoid on a velocity versus time graph will tell you
the ——————
of an object.
A. displacement
B. acceleration
C. velocity
D. distance
5. Describe the trip from your home to school using the words
position, distance, displacement, and speed.
My commute to school is a constant distance, but the time it takes to get there fluctuates owing to traffic.
What is displacement?If an object moves with respect to a reference frame, such as when a passenger travels to the back of an airliner or a professor moves to the right with respect to a whiteboard, the item's position changes.
This change in location is described as displacement.
My commute to school is a constant distance, but the time it takes to get there fluctuates owing to traffic,
The initial and the final position of the commute is the same, but the displacement varies with the route which affects my car's speed and where it is in line at stop lights.
Learn more about displacement here, refer to the link;
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A student tries to measure the period of a pendulum that is already swinging
left and right. At the moment when the pendulum is fully to the left, she
counts 'One' and starts a stopwatch. She counts successive swings each time
that the pendulum returns to the left. When she counts ‘Ten' she stops the
stopwatch, and sees that it reads 12.0 s.
a. What was her mistake?
______________________________________________________________
b. What is the period of swing of this pendulum?
______________________________________________________________
c. In this particular experiment, explain the likely effect of her reaction time
on her answer.
Answer:
a. The student's mistake was that the student did not swing the pendulum and start the watch at the same time.
b. 1.2 s per swing.
c. The likely effect of her reaction time is that they will should subtract two seconds off the time.
Explanation:
The pupil made the error of not simultaneously starting the watch and swinging the pendulum.
What is pendulum?Pendulum is defined as a body that is suspended from a fixed point and moves back and forth while being pulled by gravity. The pendulum is used to gauge the gravitational pull because the force of gravity causes it to swing back toward its average position. A pendulum's time period can be used to tell the time because it is constant.
The swing of the pendulum is 1.2 sec. per swing. They should take two seconds off the timing due to her presumably slow reaction time. A pendulum's total time should be divided by the quantity of oscillations in order to determine its time period. When compared to a pendulum with a shorter string, the one back and forth cycle of a longer-stringed pendulum requires more time to complete.
Thus, the pupil made the error of not simultaneously starting the watch and swinging the pendulum.
To learn more about pupil, refer to the link below:
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What, exactly, is moving across the medium?
Answer:
So waves are everywhere. But what makes a wave a wave? What characteristics, properties, or behaviors are shared by the phenomena that we typically characterize as being a wave? How can waves be described in a manner that allows us to understand their basic nature and qualities?
A wave can be described as a disturbance that travels through a medium from one location to another location. Consider a slinky wave as an example of a wave. When the slinky is stretched from end to end and is held at rest, it assumes a natural position known as the equilibrium or rest position. The coils of the slinky naturally assume this position, spaced equally far apart. To introduce a wave into the slinky, the first particle is displaced or moved from its equilibrium or rest position. The particle might be moved upwards or downwards, forwards or backwards; but once moved, it is returned to its original equilibrium or rest position. The act of moving the first coil of the slinky in a given direction and then returning it to its equilibrium position creates a disturbance in the slinky. We can then observe this disturbance moving through the slinky from one end to the other. If the first coil of the slinky is given a single back-and-forth vibration, then we call the observed motion of the disturbance through the slinky a slinky pulse. A pulse is a single disturbance moving through a medium from one location to another location. However, if the first coil of the slinky is continuously and periodically vibrated in a back-and-forth manner, we would observe a repeating disturbance moving within the slinky that endures over some prolonged period of time. The repeating and periodic disturbance that moves through a medium from one location to another is referred to as a wave.
Hope That Helps!!
Explanation:
A runner is training and runs past meter mark 65 and starts a stopwatch. After the runner passes meter mark 15 the stopwatch stops at 8 seconds. What was the runners velocity?
Question 5 options:
-6.25 m/s
6.25 m/s
8.13 m/s
-1.88 m/s
Answer:
-6.25 m/s
Explanation:
i took the quiz
What is the difference between physical & chemical changes?
Slate whether each is an example of a Physleat (P) or Chemteal (C) property
1. Arock's density
2. boiling point of Gatorade
3. ability of an old car to rust
4. red color of a pe apple
S ability of wood to ignite
8. bitler taste of a lemon
7. melting point of wax
8. hardness of marble
9. Luster (shininess) of gold
boiling point Gatoride
A pumpkin is thrown horizontally off of a building at a speed of 2.5 m/s and travels a horizontal distance of 12 m before hitting the ground.
What was the initial height of the pumpkin?
What was the final vertical velocity of the pumpkin?
Answer:
-47.04
Explanation:
Divide 12 m by 2.5 m/s which equals 4.8s
And then use 4.8s to multiply it with -9.8
4.8(-9.8)= -47.04 m/s
Hope this helped!! :)
The initial height of the pumpkin is 23.52m and the final vertical velocity of the pumpkin is 47.04 m/s.
Laws of motion:Initial horizontal speed, u = 2.5 m/s
horizontal distance covered , d = 12m
So the time taken is:
t = d/u
t = 12/2.5 s
t = 4.8s
Now, the initial vertical speed, v = 0
So the vertical distance traveled by the pumpkin will be equal to the initial height of the pumpkin:
s = vt + ¹/₂gt²
s = 0.5 × 9.8 × 4.8 m
s = 23.52m
Final vertical velocity:
v' = v + gt
v' = 9.8 × 4.8 m/s
v' = 47.04 m/s
Learn more about laws of motion:
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Is a ball a wheel and axle if so how do you calculate the Mechanical Advantage of the ball? If not what kind of simple machine is a ball?
1.A runner has a displacement of 20 meters in 5 seconds, what is his velocity
during this time?
Answer:
The required velocity of runner is 4m/s.
What effect will the following have on the inertia of a body if
(i) the force acting on it is increased.
(ii) the mass of the body is reduced.
Explanation:
Inertia is the tendency of a body to remain at rest or to do nothing.
It is the resistance to any change in position of body.
When the force on a body increases, the inertia reduces
When the mass is reduced the inertia reduces
According to newton's first law or the law of inertia "an object will remain in its state of rest or of uniform motion unless if it is acted upon by an external force".
with what force will the a car hit a tree if the car has a mass of 3,000 kg and a acceleration of 2m/s^2
Answer:
The answer is 6000 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 3000 × 2
We have the final answer as
6000 NHope this helps you