Answer:
Your answer is below …….
Explanation:
25. Brutus, a champion weightlifter, raises
240 kg of weights a distance of 2.35 m.
a. How much work is done by Brutus
lifting the weights?
W=Fd=mgd
= (240 kg)(9.80 m/s2)(2.35 m)
= 5.5 x 103j
b. How much work is done by Brutus
holding the weights above his head?
d=0, so no work
c. How much work is done by Brutus
lowering them back to the ground?
d is opposite of motion in part a, so
W is also the opposite, -5.5 x 103 J.
d. Does Brutus do work if he lets go of
the weights and they fall back to the
ground?
No. He exerts no force, so he does
no work, positive or negative.
If Brutus completes the lift in 2.5 s.
how much power is developed?
* = multiply
[tex]P = \frac{W}{t} = \frac{5.53 * 10x^{3} J}{2.5s} = 2.2 kW[/tex]
_____________________________________
(Hope this helps can I pls have brainlist (crown)☺️)
1. A race car accelerated from rest to 34.7 m/s by the time it crossed the finish line. The race car moved in a straight line and traveled from the starting line to the finish line in 7.81 seconds. What was the acceleration of the race car?
Answer: 4.44302176697 m/s^2
Explanation:
formula for acceleration is (final velocity - initial velocity)/time. So in your case:
(34.7m/s - 0m/s)/ 7.81s = 4.44302176697 m/s^2
How can magnets attract and repeal without touching each other?
Answer:
The hyperactivity of these electrons give magnets the ability to attract and repel
density differences in different materials are able to change the _____________ of a wave.
Answer:
Wavelength and speed both depend on the material of the medium.
Explanation:
Let [tex]f[/tex] denote the frequency of a wave. Let [tex]v[/tex] denote the speed of that wave in a given medium. Let [tex]\lambda[/tex] denote the wavelength of that wave in this medium.
The frequency [tex]f[/tex] of a wave stays the same regardless of the material of the media. However, the speed [tex]v[/tex] of a wave indeed depends on the material of the medium (density of the medium, etc.)
[tex]\lambda = v / f[/tex] and [tex]f[/tex] stays the same regardless of the medium. Thus, the wavelength [tex]\lambda[/tex] of this wave in a given medium would be proportional to the speed [tex]v[/tex] in that medium.
For example, the speed of sound in materials with a larger density (e.g., water) is generally larger than that in materials with lower density (e.g., air.)
When a sound wave travels from air into water, the frequency [tex]f[/tex] of this wave would stay the same. However, since the speed [tex]v[/tex] of the wave would increase, the wavelength [tex]\lambda[/tex] of this wave would also increase.
Which type of solid is dry ice (solid carbon dioxide)? ionic atomic molecular none of the above.
Answer: molecular solid
Explanation:
The Earth system is an example of a(n)
Inertia causes bodies to slow in their motion, unless they’re pushed by a force.
Inertia resists changes to the state of motion of a body.
Inertia decelerates a body.
Inertia is due to friction.
Answer:
ill go with B
Explanation:
inertia is the ability of a body to remain at rest or in a constant speed in a constant direction when no force is acting on it
Column A
Column B
1.
Frequency
a. Ohm
2.
Amplitude for sound
b. Decibel
3
Force
C. Joule
4
Distance
d. Newton
5.
Current
e. Amperdiet
6.
Resistance
f. Meter
7.
Voltage
g. Hertz
8.
Energy
h. Volt
Answer:its 3 and 5
Explanation:
j
A particle is constrained to move round a circle radius 382400km and makes a single revolution in 27.3 days. (i). Find the velocity in ms-1. (ii). Find its acceleration
The velocity and acceleration of the particle moving round the circle is;
Velocity = 162.12 m/s
Velocity = 162.12 m/sAcceleration = 6.873 × 10^(-5) m/s²
We are given;
Radius of circle; 382400 km = 382400000 m
Time; t = 27.3 days = 27.3 × 86400 s = 2358720 s
Now, formula for velocity is;
Velocity = distance/time
Thus;
I) velocity = 382400000/2358720
Velocity = 162.12 m/s
II) Acceleration is centripetal acceleration and is given by the formula;
a = v²/r
a = 162.12²/382400000
a = 6.873 × 10^(-5) m/s²
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A 0.14-MIN baseball is dropped from rest. It has a momentum of 0.90 kg⋅m/skg⋅m/s just before it lands on the ground.
For what amount of time was the ball in the air?
The time spent in the air by the ball at the given momentum is 6.43 s.
The given parameters;
momentum of the ball, P = 0.9 kgm/sweight of the ball, W = 0.14 NThe impulse experienced by the ball is calculated as follows;
[tex]Ft = \Delta P[/tex]
where;
[tex]Ft[/tex] is impulse
[tex]\Delta P[/tex] is change in momentum
The time of motion of the ball is calculated as follows;
[tex]t = \frac{\Delta P}{F} \\\\t = \frac{0.9 - 0}{0.14} \\\\t = 6.43 \ s[/tex]
Thus, the time spent in the air by the ball at the given momentum is 6.43 s.
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How to find direction of magnetic field.
unlock your third eye and youll be able to see it
What is unusual (compared to other planets) about how water is found on earth
Answer:
It is unique among planets in our solar system for having water in its liquid form at the surface, in an amount conducive to life evolving. ... No one knows why Earth has the exact amount of water it does, which is relatively small considering that water molecules outnumber silicate molecules in the galaxy, he said. so no one actually found out who actually put water on the earth and why
Explanation:
Answer:
It is the only planet in our solar system that has water in its liquid state at the surface in sufficient quantities to support the evolution of life. Despite the fact that water molecules outnumber silicate molecules in the galaxy, no one understands why Earth has the precise quantity of water it has, which is a minuscule amount when compared to the rest of the galaxy.
Explanation:
Hope it helps:)
What are the advantages and/or disadvantages of the radiation that technology has had for the human economy?
1. When a 50,000 kg rocket blasts off there is a large force that acts on the rocket at the moment
of take off. In 0.137 seconds, the rocket suddenly has traveled 4.2 meters. What force from
the rocket engines caused the acceleration? (Hint: first find acceleration.)
Hi there!
We can begin by calculating the acceleration using the kinematic equation:
d = vit + 1/2at²
Since the rocket starts from rest, we can rewrite this as:
d = 1/2at²
Plug in given values:
4.2 = 1/2a(0.137²) ⇒ a = 447.55 m/s²
Now, we can use Newton's Second Law to find the appropriate force:
∑F = m · a
∑F = 50,000 · 447.55 = 22,377,500 N
The launch speed of a projectile is three times the speed it has at its maximum height.what is the elevation angle at launch?
Answer:
Given: a projectile of initial launch velocity(V) and launch angle ∅ and no air resistance. At the maximum height, the projectile would have a zero contribution of speed from the vertical component(Vy) Therefore, if we say Vx=Vcos∅ is the only speed the projectile has at the instant of maximum height then we can replace Vx with 1/5V and write 1/5V=Vcos∅. Solving for the the launch angle ∅, gives Inverse Cos(1/5)=78.5 degrees.
what is refraction?
this my in sta id-:akhilrawat9453
Answer:
refers to the bending of light
the fact or phenomenon of light, radio waves, etc. being deflected in passing obliquely through the interface between one medium and another or through a medium of varying density.
why do we believe 90 percent of the mass of the milky way is in the form of dark matter?
Answer:
The orbital speeds of stars far from the galactic center are surprisingly high, suggesting that these stars are feeling gravitational effects from unseen matter in the halo.
if the magntidude of the sum and difference of two non zero vectors A and B is equal. what can we say about the two vectors
Answer:
A + B = B - A
The above equation must hold for the sum and difference to be zero.
How can one of the vectors not be zero?????
What type of energy transfer causes a sunburn?
Radiation, because particles of hot air move in space
Radiation, because electromagnetic waves transfer heat
Conduction, because hot air comes in contact with the skin
Conduction, because invisible light carries heat from the sun
Pacificaly what is the right answer A? B? C? or D? which one
Answer:
radiation
Explanation:
Answer:
B is most likely forgive me if im wrong
Explanation:
Does the dependenceof the orbital energy on nmake sense in terms of the total number of nodes in each type of orbital?.
Answer:The 2s orbital different than the 1s orbital because the 2s orbital extends farther from the nucleus than the 1s.
As we move away from the nucleus, the values of the principal quantum number (n) continues to increase.
As the principal quantum number (n) increases, the orbital becomes farther away from the nucleus.
The higher energy orbital are always larger than the orbitals closer to the nucleus.
Hence, the 2s orbital different than the 1s orbital because the 2s orbital extends farther from the nucleus than the 1s.
Explanation:
What is the difference between a low tide and a high tide
Answer:
High water level during a tide is called High tide.
Low water level during a tide is called Low tide.
A man is sitting on a chair with wheels. He grabs a 2.1 kg book from the desk and throws
the book at a speed of 7.2 m/s. His chair moves backward. The man has a mass of 70 kg and
the chair has a mass of 9.2 kg. What is the speed of the man and the chair after the book is
thrown?
The speed of the man and the chair after the book is thrown is 0.2 m/s.
The given parameters:
mass of the book, m₁ = 2.1 kgspeed of the book, u₁ = 7.2 m/smass of the man, M = 70 kgmass of the book, m = 9.2 kgThe total mass of the man and the book is calculated as follows;
m₂ = 70 kg + 9.2 kg
m₂ = 79.2 kg
The speed of the man and the chair after the book is thrown is determined by applying the principle of conservation of linear momentum;
[tex]m_1 u_1 = m_2u_2\\\\u_2 = \frac{m_1u_1}{m_2} \\\\u_2 = \frac{2.1 \times 7.2}{79.2} \\\\u_2 = 0.2 \ m/s[/tex]
Thus, the speed of the man and the chair after the book is thrown is 0.2 m/s.
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Study the three pieces of evidence for the Big Bang in this activity carefully. What is common to all these pieces of observable evidence and why does this make them much more powerful than if they did not have this common feature?
Answer:
Explanation:
the measured abundances of elementsthe observed expansion of spacethe discovery of cosmic wave backgroundThe common observable evidence are:
the measured abundances of elementsthe expansion of spacethe cosmic wave backgroundWhat is big bang?The big bang is the theory which explains that how the universe began. It says that the universe began with just a single point. It went on expanding and stretched to grow as large as possible. It is still now expanding.
The big bang consist of fully dark matter, interstellar gases or dust. The big bang is increasing just because in universe there is abundant of hydrogen and helium.
The radiations come from the big bang. These rays are also called as cosmic wave. This big bang is still on it way of expanding more.
Thus, the observational evidence are the measured abundances of element, the expansion of space and the cosmic wave background.
Learn more about big bang.
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if you were planning to escape from someone and you were tied to a chair what would you do
Which of the following correctly describes the law of conservation of matter?
Group of answer choices
A.) Matter can only be created, but not destroyed in chemical equations
B.) Matter can neither be created nor destroyed during a chemical reaction
C.) Matter can be destroyed during a chemical reaction as long as it is created again in a different reaction
D.) Matter makes up 98% of stuff in the universe, so it has to be created and destroyed sometimes
Answer:
C
Explanation:
Tama Po yan don't worry
How much work is needed to stop a 1,110 kg car that is moving straight down the
highway at 59.0 km/h?
Answer:
382.74 kJ.
Explanation:
The work that must be done to stop an 1100 kg car travelling at 59 km/h is - 382.74 kJ.
The work needed to stop an 1100 kilograms car moving with a velocity of 59.0 km/hr would be 147.72 kilojoules.
What is work done?
The total amount of energy transferred when a force is applied to move an object through some distance
The work done is the multiplication of applied force with displacement.
Work Done = Force * Displacement
As given in the problem we have to find out how much work is needed to stop a 1,110-kilogram car that is moving straight down the highway at 59.0 kilometers/hour
the mass of the car = 1100 kilograms
the velocity of the car = 59 kilometers/hour
KE = 0.5mv²
=0.5×1100×(59×1000/3600)²
= 147.72 kilojoules
Thus, the work needed to stop an 1100 kilograms car would be 147.72 kilojoules
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a 10kg model rocket is fired at a 60 degree angle from horizontal from the football field with a thrust of 200N. what is the acceleration of the rocket?
Answer:
the acceleration of the rocket is: a=vemΔmΔt−g a = v e m Δ m Δ t − g .
Explanation:
I answered this before.
hope this helps! :)
what is the molecular formula for the hydrocarbon in the mass spectrum above?
A 800N mountain climber scales a 140m cliff. How much work is done by the mountain climber?
Answer:
112 [kJ]
Explanation:
1) related formula is: A=F*S, where A - required work [J], F - force [N], S - distance [m].
2) according to the formula above: A=140*800=112000[J]=112 [kJ]
Answer:
112000 J
Explanation:
800N x 140m
Taking Earth to be a perfect sphere, find the linear speed of a point located on the 32nd parallel, as a result of Earth’s rotation. The 32nd parallel north is a circle of latitude that is 32 degrees north of the Earth's equatorial plane. Take the Earth's radius to be 6,371,000 m
The linear speed of a point located on the 32nd parallel, as a result of Earth’s rotation is 392.91 m/s
We find the linear speed of a point on the 32nd parallel from v = rω where r = radius of 32nd parallel north = Rcos32° (since it is the radius of the small circle at the 32nd parallel) where R = radius of earth = 6,371,000 m and ω = angular speed of the earth = 2π/T where T = period of earth = 24h = 24 × 60 × 60 s = 86400 s.
So, v = rω
v = Rcos32° × 2π/T
v = 2πRcos32°/T
substituting the values of the variables into the equation, we have
v = 2πRcos32°/T
v = 2π × 6,371,000 m × cos32°/86400 s.
v = 2π × 6,371,000 m × 0.8480/86400 s.
v = 33947512.5035 m/86400 s
v = 392.91 m/s
So, the linear speed of a point located on the 32nd parallel, as a result of Earth’s rotation is 392.91 m/s
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If you double the pressure of a constant amount of gas at a constant temperature, what happens to the volume
Answer: if you double the pressure, you will halve the volume. If you increase the pressure 10 times, the volume will decrease 10 times.
Explanation: