A boy and a girl are balanced on a massless seesaw. The boy has a mass of 75 kg and the girl's mass is 50 kg. If the boy sits 2.0 m from the pivot point on one side of the seesaw, where must the girl sit on the other side?
Answer:
The girl must sit 5 m on the other side of the seesaw.
Explanation:
Given;
mass of the boy, = 75 kg
mass of the girl, = 50 kg
distance of the boy from the pivot, = 2 m
let the distance of the girl from the pivot = d
<-------------2m-------------><-------------d-------------->
-----------------------------------------------------------------------------------
↓ Δ ↓
75 50
Apply the principle of moment, about the pivot;
clockwise moment = anticlockwise moment
75 x 2 = 50 x d
150 = 50d
d = 150 / 50
d = 3 m
The distance of the girl from the pivot is 3 m.
Therefore, the girl must sit ( 2m + 3m ) on the other side of the seesaw.
***URGENT****calculate the work done by a crane lifting a 3.8mg ( megagrams or tonnes) load to a height of 23m. ( g= 10 m/s squared)
Thank you, :))
Answer:
874000J
Explanation:
Given parameters:
Mass = 3.8Mg = 3.8 x 10⁶g
To kilograms;
1000g = 1kg
3.8 x 10⁶g will be 3.8 x 10³kg
height = 23m
Unknown :
Work done = ?
Solution:
The work done by a body is give as;
Work done = mgh
m is the mass
g is the acceleration due to gravity
h is the height
Now insert the parameters and solve;
Work done = 3.8 x 10³ x 10 x 23 = 874000J
Maria is trying to meet her friends at the pool but construction is blocking her path from the parking lot directly to the pool. Because of this, she has to walk 20 ft. north, 35 ft. east, and then 20 ft. south to get to the pool. Find her distance and displacement.
Answer:75 ft east
Explanation:
If a person is walking along at 1.4m/s. How long will it take that person to walk one time around a high school track?
Answer:
285.7s
Explanation:
Given parameters:
Speed of the person = 1.4m/s
Unknown:
Time it takes to walk one time round the track = ?
Solution:
The circumference of the track is 400m for a standard pitch.
Now;
Speed = [tex]\frac{distance}{time}[/tex]
Time = [tex]\frac{distance }{speed }[/tex]
Now insert the parameters;
Time = [tex]\frac{400}{1.4}[/tex] = 285.7s
At time=0s, the object is at the 21.0-meter position along the roadway. Where is the object at time = 10 s?
A) 91 m
B) 70 m
C) 140 m
D) 96 m
9. Which is the type of force that causes acceleration?
a.balanced
b.zero
c.unbalanced
Explanation:
Answer:-Unbalanced Force causes acceleration.
But why?
This is because for accelerating a body we need unbalanced forces to move it.
Hope it helps :)
how much time will it take for a bug to travel 55 M across the floor if it's traveling by 1.1 m / s
Answer:
The bug will take 50 seconds to travel 55 m across the floor if it's traveling by 1.1 m / s.
Explanation:
Given
Distance covered by bug = d = 55 m
The speed = s = 1.1 m/s
To determine
Time the bug will take to cover the distance = t = ?
Using the formula to determine the time the bug will take to travel 55 m across the floor if it's traveling by 1.1 m/s.
Distance = Speed x Time
d = s x t
t = d/s
t = 55/1.1
t = 50 s
Therefore, the bug will take 50 seconds to travel 55 m across the floor if it's traveling by 1.1 m / s.
Getting and using energy, reproducing, and maintaining structure are _______ of life.
What are combined vectors that go in one direction?
A. equal in magnitude
B. one-dimensional
C. two-dimensional
D. displacements
Answer:
One-dimensional
Explanation:
HELP!! I’m DESPERATE!! 19 POINTS!!!
Which action might lead scientists to develop new explanations about the
universe?
A. Becoming familiar with the history of space exploration
O B. Speculating on whether conditions on other planets might support
life
O C. Developing new technologies designed to see farther into space
than before
D. Wondering about the present size and shape of the universe and
how it formed
c. Developing new technologies designed to see farther into space
than before
What is universe?The universe is everything including all of space, and all the matter and energy that space contains. Also it includes time itself and, of course, it includes us.
What began as a sequence one-upmanship in space-related technological advancements between the U.S. and the Soviet Union would spawn incredible progress observed in innovation to this day. The battle for dominance not only as a global superpower, but a space power, led the United States and the Soviet Union to race to put men in space and eventually on the moon.
The launch of the Soviet satellite Sputnik on Oct. 4, 1957, would place pressure on the U.S. to design technologies crafted for space exploration. This, in turn, spurred a series of innovations in technology that would have far reaching impacts beyond space.
These technologies can be seen as developments in modern healthcare, construction, and transportation. Relevant examples include medical imaging techniques, artificial limbs, water filtration systems, solar panels, firefighting equipment, shock absorbers, air purifiers, home insulation, weather resistant airplanes, infrared thermometers, and countless other vital inventions.
While all these creations help sustain essential aspects of modern life, we carry one of the largest technological advancements from the space race in our pockets today.
Therefore, Developing new technologies designed to see farther into space than before lead scientists to develop new explanations about the universe.
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pls guys what is the law of electrostatic
Answer:
hello
Explanation:
The magnitude of the electrostatic force of attraction or repulsion between two point charges is directly proportional to the product of the magnitudes of charges and inversely proportional to the square of the distance between them
Astrology is considered a science because it is grounded in scientific research. Please select the best answer from the choices provided T
Answer:
False. Astrology is not a science.
Explanation:
Astrology is a collective term for ideas about the supposed connection between the fate of people and events on Earth and the position of the celestial bodies. It mainly concerns the places in the sky of the sun, moon and planets, which were referred to as stars in ancient times, usually against the background of the fixed stars in the Zodiac. Although astrology cannot be confirmed despite research, and scientists have long rejected the principles of astrology as pseudoscience, many people continue to practice and / or believe in it.
Answer:
False
Explanation: i got it right in edge
A 240 kg crate full of bricks is pushed across a surface with an acceleration of 1.3
m/s2. If the crate travels a distance of 4.6 m, How much work is being done?
Answer:
Workdone = 1435.2N/m
Explanation:
Given the following data;
Mass = 240kg
Acceleration = 1.3m/s²
Distance = 4.6m
To find the force;
Force = mass* acceleration
Substituting into the equation, we have;
Force = 240 * 1.3
Force = 312N
Now, to find the workdone;
Workdone = force * distance
Workdone = 312 * 4.6
Workdone = 1435.2N/m
what planet are people working on so they can move there
Answer:
mars
Explanation:
just search it up
Answer:
Mars I belive
Explanation:
WILL MARK BRAINLIEST!!!!!
How is the 3rd law different from the 1st and 2nd laws?
Answer:
In the first law, an object will not change its motion unless a force acts on it. In the second law, the force on an object is equal to its mass times its acceleration. In the third law, when two objects interact, they apply forces to each other of equal magnitude and opposite direction.
Explanation:
Hi I need help with this question (see image ).
Explanation:
a) Fixed points are the temperatures at which a thermometer is calibrated. They can refer either to the actual temperatures used for calibration, or the thermometer readings at those temperatures.
__
b) Fundamental interval is the difference between the fixed points. As with fixed points, it can refer either to the difference in actual temperature, or the difference in the corresponding thermometer readings.
The current flowing through the heating element when a toaster is plugged into a 230V mains supply, if the element has a resistance of 265Ω.
Answer:
The current flowing the heating element is 0.868 amperes.
Explanation:
Ohm's law states that voltage is directly proportional to current. In other, words, we say that:
[tex]V \propto R[/tex]
[tex]V = i\cdot R[/tex] (1)
Where:
[tex]V[/tex] - Voltage, measured in volts.
[tex]i[/tex] - Current, measured in amperes.
[tex]R[/tex] - Resistance, measured in ohms.
If we know that [tex]V = 230\,V[/tex] and [tex]R = 265\,\Omega[/tex], then the current that flows through the heating element is:
[tex]i = \frac{V}{R}[/tex]
[tex]i = \frac{230\,V}{265\,\Omega }[/tex]
[tex]i = 0.868\,A[/tex]
The current flowing the heating element is 0.868 amperes.
A bulldozer and a Mini Cooper are involved in a head-on collision. Which one experiences a greater force
Answer:
The mini Cooper will experience the greater force
Explanation:
Generally, a bulldozer has a greater mass compared to a Mini Cooper hence when both of these vehicles interact in an head on collision the Mini Cooper will experience a greater force because the bulldozer has a greater momentum
Two spherical objects have masses of 200 kg and 500 kg. Their centers are separated by a distance of 25 m. Find the gravitational attraction between them.
Answer:
1.07 x 10⁻⁸N
Explanation:
Given parameters:
Mass 1 = 200kg
Mass 2 = 500kg
Distance of separation = 25m
Unknown:
Gravitational attraction between the two bodies = ?
Solution:
To solve this problem, we use the equation of the universal gravitation;
F = [tex]\frac{G mass 1 x mass 2}{r^{2} }[/tex]
G is the universal gravitation constant = 6.67 x 10⁻¹¹Nm²kg⁻²
r is the distance
Now insert the parameters and solve;
F = [tex]\frac{6.67 x 10^{-11} x 200 x 500 }{25^{2} }[/tex] = 1.07 x 10⁻⁸N
Given:
Mass of objects,
[tex]m_1 = 200 \ kg[/tex][tex]m_2 = 500 \ kg[/tex]Distance,
[tex]r = 25 \ m[/tex]We know,
[tex]G = 6.67\times 10^{-11} \ Nm^2/kg^2[/tex]As we know the relation,
→ [tex]F_G = \frac{Gm_1m_2}{r^2}[/tex]
By substituting the values, we get
[tex]= 6.67\times 10^{-11}\times \frac{200\times 500}{(25)^2}[/tex]
[tex]= 1.0672\times 10^{-8} \ N[/tex]
Thus the above answer is right.
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You are lifting a 15 kg weight. You lift the bar 0.25 m a total of 15 times.
a. What is the total height the bar was lifted?
b. What is the force needed?
c. What is the work done?
Explanation:
Given parameters:
Mass of the weight = 15kg
Height of bar lift = 0.25m
Number of times lifted = 15times
Unknown:
Total height the bar was lifted = ?
Force needed for the lift = ?
Work done = ?
Solution:
To solve this problem we need to understand that;
Work done = Force x distance
Work done = mass x acceleration due gravity x height
Work done = weight x height
a. Total height:
Total height = 0.25 x 15 = 3.75m
b. Force needed ;
Force needed = Weight of bar = mass x gravity
= 15 x 9.8 = 147N
So;
Force used for the 15 times = 15 x 147 = 2205N
c. Work done ;
Work done = weight x height = 2205 x 3.75 = 8268.75J
Regardless of the method used to develop a scientific explanation, what does a scientist always look for?
1Trends or patterns
2proof of hypothesis
3a mathematical equation
4something never seen before
Answer:
2proof of hypothesis
Explanation:
A scientist is always on the look out for the proof of a hypothesis so as to validate their claim.
A hypothesis presented by a scientist is a testable idea. When the hypothesis is subject to a test, results are produced in form of data. The data is then analyzed to give the meaning which is the conclusion drawn So, the goal of a scientist is to find proof of their claim. The proof can come in many different forms or formatsFind the centripetal force needed to keep an 60.0 kg rider traveling in a circle in the ride.
Given:
m=
V = (from part a)
R =
Unknown:
F=?
Equation:
F= m (y^2) / r
Explanation:
Given that,
Mass of the rider, m = 60 kg
Let the radius of the circle, r = 30 cm = 0.3 m
Let the velocity, v = 20 m/s
We need to find the centripetal force needed to keep the rider in a circular path. It can be given by :
[tex]F=\dfrac{mv^2}{r}\\\\F=\dfrac{60\times (20)^2}{0.3}\\\\F=80000\\\\\text{or}\\\\F=8\times 10^4\ N[/tex]
So, the required force is [tex]8\times 10^4\ N[/tex].
. If an object travels at a constant velocity, how does its average velocity compare to its
instantaneous
velocity throughout the trip?
Answer:
The average velocity is equal to the instantaneous velocity
Explanation:
The average velocity, [tex]\overline v[/tex], is given as follows;
[tex]\overline v = \dfrac{\Delta y}{\Delta t}[/tex]
Where;
Δy = The change in displacement
Δt = The change in time
The instantaneous velocity is the derivative found of the position of the object's displacement with respect to time
Therefore, the instantaneous velocity, [tex]v_{inst}[/tex] = The limit of the average velocity as the change in time becomes closer to zero
[tex]v_{inst} = \lim_{t \to 0} \left (\dfrac{\Delta y}{\Delta t} \right ) = \dfrac{dy}{dx}[/tex]
When the velocity is constant, the displacement time graph is a straight line graph, and the slope of the displacement-time graph which is the same as the velocity is constant and therefore, we have;
[tex]Slope \ of \ straight \ line \ graph = \dfrac{y_2 - y_1}{t_2 - t_1} = \dfrac{\Delta y}{\Delta t}= \dfrac{dy}{dx}[/tex]
Therefore, for constant velocity, we have, [tex]\overline v[/tex] = [tex]v_{inst}[/tex] the average velocity is equal to the instantaneous velocity.
If mass and velocity are unknown when using de Broglie's wavelength formula, what alternative value must we have to successfully determine the wavelength
Answer:
The particle momentum, p
Explanation:
A particle's de Broglie's wavelength is an indication of the scale in length where the particle's wave-like properties are important. The symbol of de Broglie wavelength is λ or [tex]\lambda _{dB}[/tex] given as follows;
The de Broglie's wavelength formula is given as follows;
[tex]\lambda = \dfrac{h}{m \cdot v} = \dfrac{h}{p}[/tex]
Where;
λ = The wavelength of the particle in meters
v = The velocity of the particle in meters/seconds
m = The mass of the particle in kilograms
p = The momentum of the particle
h = Planck's constant = 6.626 × 10⁻³⁴ J/Hz
Therefore, the alternative value that we must have to successfully determine the wavelength if the mass and velocity are unknown, is the momentum, p of the particle.
Which is a possible result of higher air temperatures caused by global warming?
increase in sea level
freezing of polar ice caps
rapid evaporation of water in the soil
flooding of low-lying coastal areas
Answer: C. rapid evaporation of water in the soil :)
A possible result of higher air temperatures caused by global warming is rapid evaporation of water in the soil.
What is global warming and its causes and consequences?Global warming is a phenomenon that has been registered around the world during the last decades. It refers to a progressive increase in the average temperatures of the oceans and the Earth's atmosphere, which has consequences for flora and fauna, in addition to impacting critical sectors such as agribusiness.
Among the consequences of global warming are melting ice, rising sea levels, desertification, changes in rainfall, floods and reduced biodiversity.
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What is the temperature shown on the thermometer below?
A. 8 °F
B. 4 °F
C. –4 °F
D. –8 °F
Answer:
D, -8 F
Explanation:
This specific thermometer is in increments of two degrees per minor line and 10 per thicker line. Since the thermometer is showing below zero, the answer cannot be A or B since they are positive. -4 Cannot be the answer since the line addition does not make sense for that. It would be -4 if the thick line increments were 5 degrees instead of ten. Therefore if you count the lines by two from zero down to the thermometer line, you would get -8 Degrees F
A car driving at 20 m/s accelerates continuously 2m/s2 for 3 seconds. What is its final velocity
Answer: V= u+ at
V= final velocity
u=initial velocity
a=acceleration
t=time taken
V= 20 + 2*3
V= 26m/s
Explanation:
Please I need help with this question (see image).
Show workings where necessary.
Answer:
Solution:
i) Heat supplied by heater = Heat gained by water = m * c*theta = 0.12Kg * 4200 * 10 = 5040Joules in 2 minutes.
ii) Power = Energy/time = 5040J/(2 * 60seconds) = 5040J/120seconds = 42Watts.
(iii) Heat supplied to the 70g of water = m * c * theta = 0.07Kg * 4200 * 9K = 2646J
(iv) Heat supplied by heater = Heat gained by 70g of water + Heat supplied to the metal vessel.
But,from our calculations above,
Heat supplied by heater = 5040J ......and
Heat supplied to the 70g of water = 2646J
.: substituting the values,we have that :
5040J = 2646J + Heat supplied to the metal vessel.
5040J - 2646J = Heat supplied to the metal vessel.
.: Heat supplied to the metal vessel = 2394J.
(v) Heat gained by metal vessel = Heat capacity of the vessel * theta.
2394J = Heat capacity of the vessel * 9K
.: Heat capacity of the vessel = 2394/9 = 266(Joule per Kelvin)
(vi) Using the formula:
Heat Capacity = mass * specific heat capacity
.: Specific heat capacity = Heat Capacity/mass = 266/0.55 = 484(Joules per Kilogram per Kelvin)
Explanation:
________❤️ hope it helps you ❤️__________A resting state through the winter.
Adaptation: Bear sleeping in a cave during the winter months
0 A. Locomotion
B. Hibernation
C. Migration
D. Defense
Answer:
b
Explanation:
Bears hibernate in the winter
Why do water molecules tend to stay together and hold their shape? Name and explain the phenomenon by which this happens
Answer:
because liquid and solid states of water possesses intermolecular force of attraction which held the molecules of water in fixed