Answer:
decreases, stronger
newtons
Explanation:
A simple machine has efficiency 90%. What does it mean? No machine has 109 efficiency,why?
Answer:
Efficiency of a machine is 90% this means that the total energy produced to the machine only 90% is useful and given as a output.
Machines are not 100% efficient because some of the work done by a machine is used to overcome friction
A 111 kg linebacker running at 1.9 m/s and a 82 kg quarterback running at 3 m/s have a head-on collision in midair. The linebacker grabs and holds onto the quarterback. (a) What is their combined speed immediately after the collision
Answer:
Explanation:
mass of linebacker, m = 111 kg
initial velocity, u = 1.9 m/s
mass of quarterback, m' = 82 kg
initial velocity, u' = 3 m/s
(a) Let they are moving in the same direction, the velocity is v after collision.
Use conservation of momentum
m u + m' u' = (m + m') v
111 x 1.9 + 82 x 3 = (111 + 82) v
v = 2.4 m/s
Let they are moving in opposite direction, the velocity is v after collision.
Use conservation of momentum
m u - m' u' = (m + m') v
111 x 1.9 - 82 x 3 = (111 + 82) v
v = - 0.18 m/s
Given that on Earth, gravity causes an acceleration of 9.8 m/s2, what is an acceleration of 7 g?
Answer:
68.6 m/s^2
Explanation:
1 g = 9.8 m/s^2
so
7 g × 9.8m/s^2 = 68.6
Draw a wave that has a wavelength of 3 cm and an amplitude of 1 cm. Label the wavelength, the amplitude, the rest position, and the crest and trough of your wave.
Answer:
Please find attached, the required wave drawn with MS Excel
Explanation:
Functions that represent waves is given as follows
A general form of the wave equation is A·sin(B·x) + D
Where;
B = 2·π/T
T = The period of the wave = 1/f
D = The vertical shift of the wave = 0
A = The amplitude of the wave = 1 for sine wave
v = The wave velocity
λ = The wavelength of the wave
f = The frequency of the wave
v = f·λ
At constant v, λ ∝ 1/f
∴ λ ∝ T
Where T = 3, we have;
B = 2·π/T
∴ B = 2·π/3
Therefore, we have the wave with an amplitude of 1 cm, and wavelength, 3 cm, given as follows
y = sin((2·π/3)·x)
Plotting the above wave with MS Excel, we can get the attached wave
20. A semiconductor is a
crystalline solid that conducts current under any condition
metallic solid that conducts current under any condition
metallic solid that conducts current under certain conditions
crystalline solid that conducts current under certain conditions
Answer:
D. crystalline solid that conducts current under certain conditions
Explanation:
Semiconductors are crystalline solids that has the ability to conduct electrical currents but on certain conditions e.g heat. The conduction of semiconductors is less than that of conductors (metals) but more than insulators (nonmetals), hence, they are said to be intermediates of conductors and insulators in terms of electrical conductivity.
Examples of semiconductors are silicon, boron, carbon, germanium, arsenic etc.
physics as a subject involves measurement and estimation,giving examples of everyday life situations, explain the meaning and what is done in each case
Answer:
57
Explanation:
importance of measurement in our dairy life
Answer:
in order to know the length of something
The density of a material in CGS system of units is 4g cm-³. In a system of units in which unit of length is 10 cm and unit of mass is 100g, the value of density of material will be...?
1) 0.04
2) 40
3) 0.4
4) 400
[tex]\sf\underline{Solution:}[/tex]
Here , the density of the material is 4g cm³ but it is not given in CGS system.
$\sf{As\:we\:know\:that:}$
$\sf\bold{Density=}$ $\sf\dfrac{Mass}{Volume}$
$\space$
[tex]\sf{Now,according \: to \:the\:question:}[/tex]
$\sf\small{Density\:of\:the\:material=4}$ $\sf\dfrac{g}{cm^2}$
$\space$
$\sf{It\:is\:given\:that:}$
In the system of units the mass is 100gram.
$\space$
Hence,
$\sf{The\:mass\:unit\:for\:4g=}$ $\sf\dfrac{4}{100}$ $\sf{units}$
$\space$
In the system of units,the length is 10cm.
Henceforth,
$\sf\small{The\:length \:for\:1cm\:units=}$ $\sf\dfrac{1}{10}$ $\sf{units}$
$\space$
☆ Substitute the required values in the given formula-
$\sf\purple{Density=}$ $\sf\dfrac\purple{Mass}\purple{volume}$
$\space$
$\sf\underline\bold{Density\:of\:the\:material:}$
= $\sf\dfrac{4/100}{1/10^3}$ $\sf\bold{units}$
$\space$
= $\sf\dfrac{4/100}{1/1000}$ $\sf\bold{units}$
$\space$
= $\sf\dfrac{4000}{100}$ $\sf\bold{units}$
$\space$
$\sf\underline\bold\blue{=40\:units}$
$\sf\small{Therefore,option\:2nd\:is\:correct!}$
_______________________________
in california the pacific plate slides past the north american plate. If the pcific plate is moving at a speed of 5 centimeters per year, how long will take for the plate to travel 100 meters
Answer:
6.34×10⁹ seconds
Explanation:
Applying,
V = d/t............. Equation 1
Where V = speed plate, d = distance covered by the plate, t = time it takes the plate to travel
make t the subject of the equation
t = d/V............ Equation 2
From the question,
Given: d = 5 cm/yr = (5×3.154×10⁻⁹) = 1.577×10⁻⁸ m/s, d = 100 meter
Substitute these values into equation 2
t = 100/1.577×10⁻⁸
t = 6.34×10⁹ seconds
Hence the time it takes the the plate to travel is 6.34×10⁹ seconds
Hideki had normal vision for most of his life, but now that he is in his 60s, he has started to have difficulty focusing on near objects. He went to an optometrist, who explained that his vision problem was the result of the lenses in his eyes losing elasticity due to aging. Which condition does Hideki have
Answer:
He is suffering from hypermetropia.
Explanation:
There are some defects of vision.
Longsightedness of hypermetropia : It is the defect of vision in which the person is not able to see the nearby objects clearly but can see the far off objects clearly. This is due to the elongation of size of eye ball. It is cured by using convex lens of suitable focal length.
Nearsightedness or Myopia : It is the defect of vision in which a person is not able to see the far off objects clearly but can see the nearby objects clearly. It is due to the contraction in the size of eye ball. It is cured by using concave lens of suitable focal length.
So, Hideki is suffering from hypermetropia. So, he should use the convex lens of suitable focal length.
Which of the following is an example of a molecule?
A. A sodium atom forms a metallic bond with another sodium atom.
B. A hydrogen atom forms a covalent bond with a chlorine atom.
C. A sodium atom forms an ionic bond with a chlorine atom.
D. A sodium atom forms a metallic bond with another sodium atom.
Answer:
C
Explanation:
write any two uses of a wedge.
Answer: two uses of a wedge can be to tighten things as well as to lift things.
Explanation: because that is some things wedges (a mechanical tool) can do.
A man has 60w bulbs and a 240w water heater in his apartment. If the bulbs and the water heater are switched on for four hours daily and the cost of electricity is N1.20 per KWh calculare his bill in 30 days
Answer: [tex]N43.2[/tex]
Explanation:
Given
Power consumption of bulb and water are [tex]60\ W[/tex] and [tex]240\ W[/tex]
If the Devices are on for four hours
Total power of devices [tex]60+240=300\ W[/tex]
Energy consumed for 4 hours is
[tex]\Rightarrow 300\times 4=1200 Wh\\\Rightarrow 1.2\ kWh[/tex]
For 30 days it is [tex]1.2\times 30=36\ kWh[/tex]
Cost for 30 days [tex]36\times 1.2=43.2\ N[/tex]
A 250g object hangs from a spring that has a spring constant of 48.0 N/m and oscillates with an amplitude of 5.42cm
1)The magnitude of the objects acceleration when the displacement is 4.27 cm (down) is __ m/s^2
2)Given that the object has an amplitude of 5.42 cm the maximum speed that the object is __m/s
Explanation:
Given that,
Mass of an object, m = 250 g = 0.25 kg
Spring constant, k = 48 N/m
The amplitude of the oscillation, A = 5.42 cm = 0.0542 m
1. At equilibrium,
ma = kx
Where
a is the acceleration of the object
So,
[tex]a=\dfrac{kx}{m}\\\\a=\dfrac{48\times 0.0542}{0.25}\\\\a=10.4\ m/s^2[/tex]
2. The maximum speed of the object is :
[tex]v=A\omega\\\\v=A\sqrt{\dfrac{k}{m}}\\\\v=0.0542\times \sqrt{\dfrac{48}{0.25}}\\\\v=0.75\ m/s[/tex]
Hence, this is the required solution.
The first periodic table of elements Mendeleev created contained only 70 elements. True or false?
Explanation:
FALSE
The first periodic table of elements Mendeleev created contained 63 elements.
If the wave is detected 12.5 minutes after the earthquake, estimate the distance from the detector to the site of the quake
Answer:
Remember the relation:
Speed*Time = Distance.
We can estimate that the speed at which an earthquake "moves", in the surface, is:
S = 6km/s (this is a low estimation actually)
Then if the wave is detected 12.5 minutes after the earthquake, we know that it traveled for 12.5 minutes before reaching the detector.
So we know the speed of the wave and the time it took to reach the detector, then we can use the equation:
Speed*Time = Distance.
to find the distance.
First, we should write the time in seconds
we know that:
1 min = 60 s
then:
12.5 min = 12.5*(60 s) = 750 s
Then, the wave traveled with a speed of 6 km/s for 750 seconds until it reached the detector, then the distance that it traveled is:
(6km/s)*750s = 4500 km
The distance between the detector and the site of the quake is around 4500 km.
How does 'g' vary from place to place?
Explanation:
The acceleration g varies by about 1/2 of 1 percent with position on Earth's surface, from about 9.78 metres per second per second at the Equator to approximately 9.83 metres per second per second at the poles.
The speed of sound where a tuning fork of frequency 262 Hz produces the third resonance position above a closed air column that is 1.59 m in length is ___m/s.
Answer:
v = 333.26 m/s
Explanation:
Given that,
The frequency of the tuning fork, f = 262 Hz
It produces the third resonance position above a closed air column that is 1.59 m in length.
We need to find the speed of sound in tuning fork. Let it is f. The third resonance position corresponds to the fifth harmonic of the closed air column. The wavelength in third resonance is given by :
[tex]\lambda=\dfrac{4}{5}L\\\\=\dfrac{4}{5}\times 1.59\\\\=1.272\ m[/tex]
The speed of sound is :
[tex]v=f\lambda\\\\=262\times 1.272\\\\=333.26\ m/s[/tex]
So, the speed of sound is 333.26 m/s.
Answer:
The speed of sound is 555.44 m/s.
Explanation:
frequency of third resonance position, f''' = 262 Hz
length of pipe, L = 1.59 m (closed)
Let the speed is v.
The frequency of third resonance in closed organ pipe is
[tex]f''' =\frac{3 v}{4 L}\\\\262 = \frac{3 v}{4\times 1.59}\\\\v = 555.44 m/s[/tex]
if you rub a ballon with wool or duster it can charge it negatively where do these extre charge come from?
Answer:
The electrons come from the free electrons in wool which contains moisture or other forms of additives that creates impurity centers which causes the wool to be electrically conductive
Explanation:
Wool which is mixed with certain substances, conducts electricity in a manner similar to the wool-water system that give rise to centers of impurities where electrical conduction takes place
The ability to conduct electricity is related to the presence of free electrons on a material. Therefore, when a balloon, which is an insulator, is rubbed with wool, some of the mobile electrons on wool, which is also an insulator without the presence of substances that aid its electrical conductivity, are transferred to the balloon, thereby making the balloon to be negatively charged
Answer:
am I the only one seeing blink
a bubble of gas rises to the surface of a soft drink. this is because
Một mạch kín hình vuông cạnh 20cm đặt vuông góc với 1 từ trường đều có độ lớn thay đổi theo thời gian. Trong khoảng thời gian 0,01s , cho độ lớn cảm ứng từ tăng đều từ 0 lên đến 0,05T. Biết điện trở của mạch là 0,5. Tính cường độ dòng điện cảm ứng trong mạch
Answer:
please do write it in english
Một người đi xe ô tô từ a đến b cách nhau 90km trong nửa quãng đường đầu người dó đi với vận tốc v1 trong nửa quãng đường sau người đó đi với vận tốc v2=2v1/3.Tính vận tốc của người đó trên mỗi chặng đường để sau 1.5h người đó đi đến b
Answer:
The speed of the first half is 75 km/h and for the second half is 50 km/h.
Explanation:
A person driving a car from a to b 90km apart for the first half of the distance travels with speed v1 the second half of the distance travels with a speed of v2=2v1/3. Calculate his speed per each the distance so that after 1.5 hours that person reaches b
Total distance, D = 90 km
Let the time for he first half is t and for the second half is t'.
Distance = speed x time
45 = v1 x t .... (1)
And
45 = v2 x t' .... (2)
Total time is T = t + t'
[tex]1.5 = \frac{45}{v_1}+\frac{45}{v_2}\\\\1.5 = \frac{45}{v_1}+\frac{3\times 45}{2v_1}\\\\1.5 = \frac{90+135}{2v_1}\\\\3v_1 = 225 \\\\v_1 = 75 km/h[/tex]
Now, v2 = 2 x 75/3 = 50 km/h
what is the direction of magnetic lines of force outside the magnet
please mark me as brainiest p
Explanation:
Magnetic lines of force are closed curves. C) Outside the magnet their direction is from north pole to south pole and inside the magnet these are from south to north pole.
An instructor wishes to determine the wavelength of the light in a laser beam. To do so, he directs the beam toward a partition with two tiny slits separated by 0.195 mm. An interference pattern appears on a screen that lies 5.10 m from the slit pair. The instructor's measurements show that two adjacent bright interference fringes lie 1.55 cm apart on the screen. What is the laser's wavelength (in nm)
Answer:
λ = 610.6 nm
Explanation:
We are given;
Separation distance; d = 0.195 mm = 0.195 × 10^(-3) m
Interference pattern distance; D = 4.95 m
Width of the two adjacent bright interference; β = 1.55 cm = 1.55 × 10^(-2) m
Formula for the Fringe width is;
β = Dλ/d
Where;
λ is laser's wavelength
Thus;
λ = (d × β)/(D)
λ = (0.195 × 10^(-3) × 1.55 × 10^(-2))/4.95
λ = 610.6 × 10^(-9) m
λ = 610.6 nm
maize is a monocotyledonous seed and pea is a dicotyledonous seed why? give short and the suitable answer I will mark you as a brainelist
Answer:
A dicot is a flowering plant that has one seed leaves. The monocot plants have a single cotyledon. Maize only has one cotyledon in their seed, so it's a monocot. Seeds having two Cotyles are mainly called a Dicot. A pea is a dicotyledonous plant, the seed (the pea itself) has two halves, cotyledons, hence dicot being 2.
Explanation:
One or more of the cotyledons are the first to appear from a germinating seed. Based on the number of cotyledons, botanists classify flowering plants (angiosperms) into :
a) plants with one embryonic leaf, termed monocotyledonous (monocots).
b) plants with two embryonic leaves, termed dicotyledonous (dicots).
Helpful Link:
https://www.vedantu.com/question-answer/in-pea-caster-and-maize-the-number-of-cotyledons-class-11-biology-cbse-5f626a17e5bde9062ff6d2a3
A conversion factor is a ratio of ____ measures
Opposite
Larger
Smaller
Equivalent
Answer:
Equivalent
A conversion factor is a ratio of equivalent measures
how is speed different from velocity
Answer:
Speed is a time for how long an object is moving
Velocity is the direction of an object
A motorcycle is moving at a constant velocity of 15 meters/second. Then it starts to accelerate and reaches a velocity of 24 meters/second in 3 seconds. What’s the acceleration of the motorcycle over this time? Use .
A.
9 m/s2
B.
8 m/s2
C.
6 m/s2
D.
5 m/s2
E.
3 m/s2
option E
3m/s square
hope it helped u
determjne the density of liquid whose relative density is 1.25 given that the density is 1000kgm-3
Explanation:
Relative density=density of liquid÷density of water
1.25=x ÷ 1000
x=1.25 × 1000
x=1250kgm^-3
