Answer:
50%
Explanation:
Given parameters:
Work output = 30J
Work input = 60J
Unknown:
Efficiency of the lever = ?
Solution:
To solve this problem, the efficiency is taken as the ratio of the work output to that of the work input;
Efficiency = Work output / Work input x 100
Efficiency = [tex]\frac{30}{60}[/tex] x 100 = 50%
A researcher asks the same group of kids to define "happiness" when
they were 5 years old, 10 years old, and again at 20 years old. They then
analyzed how the kids' idea of "happiness" changed over the years. This is
an example of which type of study?
case study
cross-sectional study
longitudinal study
naturalistic observation
double blind study
Answer:
naturalistic observation
Explanation:
A standard 1 kilogram weight is a cylinder 40.0 mm in height and 53.5 mm in diameter. What is the density of the material?
Answer:
1.15*10^-5 kg/m^3
Explanation:
Given data
mass= 1kg
hieght= 40 mm
diameter= 52.5mm
radius= 53.5/2= 26.25mm
The volume of the cylinder
V=πr^2h
V=3.142*26.25^2*40
V=3.142*689.0625*40
V=86601.375 mm^3
Density= mass/volume
Density= 1/86601.375
Density=0.00001154716
Density= 1.15*10^-5 kg/m^3
Hence the density is 1.15*10^-5 kg/m^3
List ten different muscles of the body and label what type of muscle it is.
Answer:
Masseter
The masseter runs from the temporal bone (that forms part of the sides and base of the skull) to the lower jaw (the mandible). It lifts the lower jaw, to close the mouth. The masseter is the strongest muscle in your body.
Temporalis
The temporalis begins on two bones of the skull, at the front (the frontal) and at the side and base (the temporal). It runs to the top of the lower jaw (the mandible). Like the masseter, the temporalis helps close the mouth.
Deltoid
The deltoids are the triangular muscles of the shoulder. The strongest point is the central section, which raises the arm sideways. The front and back parts of the muscle twist the arm. Deltoid comes from the Greek word deltoeides, meaning shaped like a (river) delta, which is triangular.
Pectoralis major
(The pecs!) The pectoralis major is a large, fan-shaped muscle. It covers much of the front upper chest, beginning at the breastbone (or sternum) including the second to the sixth ribs.
Adductor Longus
The adductor longus is located on the inner thigh. Adduct means move, so this muscle allows the thigh bone (the femur) to move inward and to the side.
Soleus
Located in the lower leg, the soleus runs from the lower leg bones (the tibia and fibula) to the heel (the calcaneus). The soleus muscle flexes the foot by moving the foot at the ankle. It also helps circulation by pumping blood back up towards the head.
Biceps brachii
The biceps brachii runs from the shoulder to the elbow. It is attached to the shoulder blade (the scapula), and extends along the front surface of the upper arm bone (the humerus). When the bicep contracts, the arm bends at the elbow. Notice that humerus sounds like humour – we call this area of the elbow the funny bone.
The Buccinator
The buccinator muscle compresses the cheek. This muscle allows you to whistle, blow, and suck; and it contributes to the action of chewing.
The Suprahyoid
The suprahyoid muscles raise the hyoid bone, the floor of the mouth, and the larynx during deglutition.
The Splenius
The splenius muscles originate at the midline and run laterally and superiorly to their insertions. From the sides and the back of the neck, the splenius capitis inserts onto the head region, and the splenius cervicis extends onto the cervical region. These muscles can extend the head, laterally flex it, and rotate it.
does it take more force to slow something down than to speed it up.
If an object must be slowed quickly, the force applied to it must be greater than that required for gradual slowing. For example, the greater the force applied to a bicycle's brakes, the faster it will slow or stop.
What is force?A force is an influence in physics that can change the motion of an object. A force can cause a mass object to change its velocity, or accelerate.
Intuitively, force can be described as a push or a pull. A force is a vector quantity because it has both magnitude and direction.
Force is defined as the tendency of a body to modify or change its state as a result of an external cause. When applied force, the body can also change shape, size, and direction.
The same force that was used to accelerate something can be used to slow it down. It will stop faster if more force is applied.
Thus, it can be concluded that it take more force to slow something down than to speed it up.
For more details regarding force, visit:
https://brainly.com/question/13191643
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Twice a year the Sun’s rays strike Earth north or south of the....
Answer:
Tropic of Cancer in the north and the Tropic of Capricorn in the south.
Explanation:
Which statement best describes how scientists and engineers work together
in the research and development cycle?
O A. Engineers make a new discovery about nature, and then scientists
do experiments to verify it.
O B. Scientists develop new technology, and then engineers use it to
solve design problems.
C. Scientists make a discovery, and then engineers use it to help
them solve problems with their designs.
D. Engineers develop a new technology, and then scientists use it to
solve design problems.
Answer:
C
Explanation:
A 0.144-kg baseball is moving toward home plate with a speed of 43 m/s when
it is bunted. The bat exerts an average force of 6,500-N on the ball for 0.00135.
The pitcher throws in the positive x direction. (The Force will act in the -
direction).
At a swim meet, swimmer A swims 50 m in 12 s, swimmer B in 13 s, swimmer C in 11 s, and
swimmer D in 14 s. The race involved swimming back and forth one time. Which swimmer had
the greatest displacement?
Answer:
Swimmer B had the greatest displacement:)
Explanation:
Hope you do great! :)
brainliest would be nice:)
What effect does inertia have on the motion of an object?
Answer:
Inertia is the tendency of an object to resist a change in its motion. Because of inertia, a resting object will remain at rest, and a moving object will keep moving. Objects with greater mass have greater inertia
Does a Magnesium atom gains 2 electrons in an ionic compound?
Answer:
Yes
Explanation:
Example of ionic bonding takes place between magnesium(mg) and oxygen(02) to form magnesium oxide (mg0).... Magnesium loses two electrons to form Mg2+, and oxygen gains two electrons to form 02-
what is a physical benefit of stretching
A 4500 kg Honda Civic, a 0.5 kg Matchbox car, and a 45 kg Power Wheel
are each pushed with a 30 N force. Which car will have the GREATEST
acceleration?
You have to balls heading towards you. One of them is football (lighter with higher velocity) and the other one is a bowling ball (heavier with lower velocity). They have the same momentum. There are no other variables included. Which one would be easier to catch. Explain why.
Answer:
The Football
Explanation:
They have the same velocity, but different shapes and weight. Although the balling ball would be easier to stop (due to slow velocity), but if you see a bowling coming your way in the air, GET OUT OF THE WAY!
If a 1 kg book has 46 Joules of gravitational potential energy how high is the shelf it is on?
g = 9.8 m/s^2 KE = ½ mv^2 PE = mgh
Answer:
4.7m
Explanation:
Given parameters:
Mass of the book = 1kg
Gravitational potential energy = 46J
Unknown:
Height of the shelf = ?
Solution:
The potential energy is due to the position of a body above the ground.
Gravitational potential energy = mgh
m is the mass,
g is the acceleration due gravity = 9.8m/s²
h is the height which is unknown
46 = 1 x 9.8 x h
h = 4.7m
The place below earth's surface where the earthquake begins.
а
focus
fault
en oo
epicenter
P-wave
Answer:
The position where an earthquake begins below the earths surface is called the hypo center. The point directly above the hypo center is called the epicenter.
Explanation:
www.usga.gov | United States of America Department of Geological Surveys.
true or false total distance of amoving body can be negative
Answer:
False
Explanation:
the total distance of a moving body is always positive
Distance is the total distance between any two points
A 95 kg clock initially at rest on a horizontal floor
requires a 650 N horizontal force to set it in motion.
After the clock is in motion, a horizontal force of 560N
keeps it moving with a constant speed. Find Msand uk
between the clock and the floor.
Answer:
You are given that the mass of the clock M is 95 kg.
This is true whether the clock is in motion or not.
Fs is the frictional force required to keep the clock from moving.
Thus Fk = uk W = uk M g the force required to move clock at constant speed. (the kinetic frictional force)
uk = 560 N / 931 N = .644 since the weight of the clock is 931 N (95 * 9.8)
us is the frictional force requited to start the clock moving
us = static frictional force = 650 / 931 -= .698
help plz any one
1. In each of the following questions find the density. State the units of your answer.
Mass 45g, volume 5cm3
Answer:
Explanation:
Density=mass÷volume
=45÷3
=15
How is motion related to balanced and unbalanced forces?
Answer:
When the motion of an object changes, the forces are unbalanced. Balanced forces are equal in size and opposite in direction. When forces are balanced, there is no change in motion.
Explanation:
Given that the mass of Earth is 5.98x1024 kg, what is the orbital radius of a satellite that has an orbital period of
exactly one day (assume that a day is exactly 24 hours in length)?
Answer:
The orbital radius is approximately 42,259 kilometers.
Explanation:
From Newton's Law of Gravitation we find that acceleration experimented by the satellite ([tex]a[/tex]), measured in meters per square second, is defined by:
[tex]a = \frac{G\cdot M}{r^{2}}[/tex] (1)
Where:
[tex]G[/tex] - Gravitational constant, measured in cubic meters per kilogram-square second.
[tex]M[/tex] - Mass of Earth, measured in kilograms.
[tex]r[/tex] - Orbital radius, measured in meters.
By supposing the satellite rotates at constant speed and in a circular path, we find that acceleration is entirely centripetal and can be defined in terms of period, that is:
[tex]\frac{4\pi^{2}\cdot r}{T^{2}} = \frac{G\cdot M}{r^{2}}[/tex]
[tex]4\pi^{2}\cdot r^{3} = G\cdot M\cdot T^{2}[/tex]
[tex]r^{3} = \frac{G\cdot M\cdot T^{2}}{4\pi^{2}}[/tex]
[tex]r = \sqrt[3]{\frac{G\cdot M\cdot T^{2}}{4\pi^{2}} }[/tex]
Where [tex]T[/tex] is period, measured in seconds.
If we know that [tex]G = 6.674\times 10^{-11}\,\frac{m^{3}}{kg\cdot s^{2}}[/tex], [tex]M = 5.98\times 10^{24}\,kg[/tex] and [tex]T = 86400\,s[/tex], then orbital radius of the satellite is:
[tex]r = \sqrt[3]{\frac{\left(6.674\cdot 10^{-11}\,\frac{m^{2}}{kg\cdot s^{2}} \right)\cdot (5.98\times 10^{24}\,kg)\cdot (86400\,s)^{2}}{4\pi^{2}} }[/tex]
[tex]r \approx 42.259\times 10^{6}\,m[/tex]
[tex]r \approx 42.259\times 10^{3}\,km[/tex]
The orbital radius is approximately 42,259 kilometers.
A particle moving along the x-axis has its velocity described by the function vx =2t2m/s, where t is in s. Its initial position is x0 = 1.3 m at t0 = 0 s
Answer:
Follows are the solution to this question:
Explanation:
In point a:
Place of particles
[tex]X(t)=\int V_{x}(t)dt[/tex]
[tex]=\int 2t^{2}dt\\\\=\frac{2}{3}t^{3}+C[/tex]
[tex]\to t=0\\\\ \to X(0)=2.3 \ m[/tex]
[tex]\to X(0)=0+C\\\\ \to C=2.3\ m[/tex]
[tex]\to X(t)=( \frac{2}{3})t^3 + 2.3\\\\ \to t=2.2\\\\\to X=( \frac{2}{3})\times 2.2^3 +2.3 \\\\[/tex]
[tex]= \frac{2}{3}\times 10.648 +2.3\\\\= \frac{21.296}{3}+2.3\\\\ = 7.09+2.3\\\\ =9.39\\\\ =9.4\ m[/tex]
In point b:
when [tex]t=2.2 \ s[/tex]
the Particle velocity [tex](V)=2 \times 2.22 =9.68\ \frac{m}{s}[/tex]
In point c:
Calculating the Particle acceleration:
[tex]\to a=\frac{dV}{dt} =4\ t\\\\\to t=2.2 \ s\\\\\to a=4\times 2.2 =8.8 \ \frac{m}{s^2}[/tex]
The thymus gland plays an important role in the developing immune system of a child. It makes infection-fighting lymphocytes called
.
Answer:
give brainliest please
Explanation:
T- lymphocytes or T cells
How does momentum play in tackling?
Answer:
When two players are running full speed at each other on a football field they build up their momentum
When applying a force to a book on a desk, the force must be greater than the force of
the book to begin moving.
What is the ƒ if v = 50 m/s and λ = 10 m?
Answer:
5Hz
Explanation:
I hope that by stating f you mean frequency
so I think people in this app just like to give answers without explaining so let me try to explain to you why
first of all, you must know the formula
which is velocity = frequency x wavelengthjust insert the values in
50 = 10 x frequency
50/10 = frequency
5 = frequency
Describing the Changes in the Ator Based on the article "Will the real atomic model please stand up?,"describe one major change that occurred in the development of the modern atomic model.
Answer: the last period. i think has the largest energy level
Explanation:
Answer:
honestly?
Explanation:
the atoms changed
A cube icebox of side 3cm has a thickness of 5.0cm. If 4.0 kg of ice is put in the box estimate the amount of ice remaining after 6hrs. The outside T° is 45°c and coefficient of thermal conductivity of thermacole is 0.01J /s/m/k. The heat of fusion of water is 3.35× 10^5 J/k/hr/kg
Answer:
The amount of solid ice remaining after 6 hours is approximately 3.68664 kg
Explanation:
The given parameters are;
The side length of the cube box, s = 3(0) cm = 0.3 m
The thickness of the cube box, d = 5.0 cm = 0.05 m
The mass of ice in the box, m = 4.0 kg
The outside temperature of the cube box, T₁ = 45°C
The temperature of the melting ice inside the box, T₂ = 0°C
The latent heat of fusion of ice, [tex]L_f[/tex] = 3.35 × 10⁵ J/K/hr/kg
The surface area of the box, A = 6·s² 6 × (0.3 m)² = 0.54 m²
The coefficient of thermal conductivity, K = 0.01 J/s·m⁻¹·K⁻¹
For thermal equilibrium, we have;
The heat supplied by the surrounding = The heat gained by the ice
The heat supplied by the surrounding, Q = K·A·ΔT·t/d
Where;
ΔT = T₁ - T₂ = 45° C - 0° C = 45° C
ΔT = 45° C
Q = K·A·ΔT·t/d = 0.01 × 0.54 × 45 × 6× 60×60/0.05 = 104976
∴ The heat supplied by the surrounding, Q = 104976 J
The heat gained by the ice = [tex]L_f[/tex] × [tex]m_{melted \ ice}[/tex] =3.35 × 10⁵ J/kg × [tex]m_{melted \ ice}[/tex]
Therefore, from Q = [tex]L_f[/tex] × [tex]m_{melted \ ice}[/tex], we have;
Q = 104976 J = [tex]L_f[/tex] × [tex]m_{melted \ ice}[/tex] = 3.35 × 10⁵ J/kg × [tex]m_{melted \ ice}[/tex]
104976 J = 3.35 × 10⁵ J/kg × [tex]m_{melted \ ice}[/tex]
[tex]m_{melted \ ice}[/tex] = 104976 J/(3.35 × 10⁵ J/kg) ≈ 0.31336 kg
The mass of melted ice, [tex]m_{melted \ ice}[/tex] ≈ 0.31336 kg
∴ The amount of solid ice remaining after 6 hours, [tex]m_{ice}[/tex] = m - [tex]m_{melted \ ice}[/tex]
Which gives;
[tex]m_{ice}[/tex] = m - [tex]m_{melted \ ice}[/tex] = 4.0 kg - 0.31336 kg ≈ 3.68664 kg
The amount of solid ice remaining after 6 hours, [tex]m_{ice}[/tex] ≈ 3.68664 kg.
A boy finds an abandoned mine shaft in the woods, and wants to know how deep the hole is. He drops in a stone, and counts 3 seconds before he hears the "plunk" of the stone hitting the bottom of the shaft. Approximately how deep is the shaft? (Assume a gravitational acceleration of 9.8 m/s2 and no significant air resistance.)
Answer: 9.81 times 3s= 29.43m/s
so 29.43 m/s times 3= 88.29m
Explanation:
Margy is trying to improve her cardio endurance by performing an exercise in which she alternates walking and running 100.0 m each. If Margy is walking at 1.4 m/s and accelerates at 0.20 m/s2 during one of the running portions, what is her final velocity at the end of the 100.0 m? Round your answer to the nearest tenth. m/s
Answer:
6.5 m/s
Explanation:
We are given that
Distance, s=100 m
Initial speed, u=1.4 m/s
Acceleration, [tex]a=0.20 m/s^2[/tex]
We have to find the final velocity at the end of the 100.0 m.
We know that
[tex]v^2-u^2=2as[/tex]
Using the formula
[tex]v^2-(1.4)^2=2\times 0.20\times 100[/tex]
[tex]v^2-1.96=40[/tex]
[tex]v^2=40+1.96[/tex]
[tex]v^2=41.96[/tex]
[tex]v=\sqrt{41.96}[/tex]
[tex]v=6.5 m/s[/tex]
Hence, her final velocity at the end of the 100.0 m=6.5 m/s
Answer:
6.5
Explanation:
An object is continuously changing its velocity by the same rate. What is true about this object?
А The object has decreasing acceleration
B
The object has increasing acceleration.
С
The object has zero acceleration.
D
The object has constant acceleration.
Answer:
DThe object has constant acceleration.Explanation:
I hope it helps
