Answer:
a)
there r two types of motion, uniform and non-uniform
uniform means equal distance travelled at equal intervals of time
and non-uniform is exactly the opposite.
b)
quantities which can be represented by magnitude along r called scalar quantities such as speed.
quantities which need magnitude along with direction r called vector quantities such as velocity.
c)
velocity=10m/s
acceleration = u-v/s i.e initial final velocity - initial velocity upon time
acceleration= 0.2m/s sq
time= 30s
10 = displacement/time
10 = x/30
10 = 300
Answer is 300 meters - distance/displacement.
What kind of image is formed by an object that is placed beyond the center of curvature on the principal axis of a concave mirror?
A.
real, inverted, the same size as the object, and at the same distance as the object
B.
real, inverted, larger than the object, and farther from the mirror than the object
C.
virtual, upright, left-right reversal, the same size as the object, and at the same distance as the object
D.
real, inverted, smaller than the object, and closer to the mirror than the object
E.
virtual, upright, larger than the object, and farther from the mirror than the object
Answer:D.
Real, inverted, smaller than the object, and closer to the mirror than the object
Explanation: Real images will be inverted. As it is beyond the centre of curvature it is also beyond 2F which means that the image is inside the centre of curvature ( between F and 2F from the mirror ) As the image is closer to the mirror than the object it must be diminished in size
Which quantity must equal zero if a car is moving at a constant rate along a straight line?
A. direction of the car
B. energy of the car
C. speed of the car
D. acceleration of the car
The acceleration of the car must equal zero if a car is moving at a constant rate along a straight line.
What forces are acting on a car moving at a constant speed?A car moving at a constant speed (uniform motion) has all forces acting on it balanced. In this case, the two backward forces (air resistance and friction) perfectly balance the applied force of the wheels on the road in the opposite direction.
When the car is moving at a constant speed?Acceleration is defined as the rate of change in speed. So if the car is moving at a constant speed that means the rate of change in speed is zero. Hence, acceleration is zero.
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What is the product of an oxidation reaction?
Ozone
Oxygen
Oxide
Answer:
Oxide
Explanation:
Ozone and oxygen are oxidising agents
[tex]O _{3} \: \: ozone \\ \\ O _{2} \: \: oxygen[/tex]
Answer:
Oxygen
Explanation:
The name oxidation actually originates from the word oxygen so the question answers it's self.
In case you don't know what oxidation is:
Oxidation occurs when an atom, molecule, or ion loses one or more electrons in a chemical reaction. When oxidation occurs, the oxidation state of the chemical species increases. Oxidation doesn't necessarily involve oxygen! Originally, the term was used when oxygen caused electron loss in a reaction.
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mechanical energy is two types ??
Answer:
Yes Kinetic and Potential energy
A student uses 80 joules of energy to lift a backpack in a time of 0.75 seconds. How much power
does the student have?
Answer:
P = 106.7 W
Explanation:
Given that,
Work done in lifting a backpack, W = 80 J
It is lifted in 0.75 seconds
We need to find the power of the student. The power of an object is defined as work done per unit time. So,
[tex]P=\dfrac{W}{t}[/tex]
Put all the values,
[tex]P=\dfrac{80}{0.75}\\\\P=106.7\ W[/tex]
So, the power of the student is 106.7 W.
a sample contains 110 g of a radioactive isotope. how much radioactive isotope will remain in the sample after 1 half-life?
a. 100g
b. 25 g
c. 75 g
d. 50 g
Answer:
The half-life of a radioactive isotope is the time such that the initial amount of the isotope is reduced to its half.
Thus, if we start with A grams of a given radioactive isotope, after a 1 half-life, we will have A/2 grams of the radioactive isotope.
In this case, we know that the sample has 110g of a radioactive isotope.
Then, after 1 half-life, we should have half of 110g, which is:
110g/2 = 55g
Then we should have 55 g of a radioactive isotope.
The answer that is closer to this result is option d (50 g), so that is the correct one.
Which of the following best describes a nebula?
Explanation:
is a formation in space which is constituted mostly of helium, dust and other gases in various concentration
Task: At the end of the lesson you will be asked to develop a final writing assignment on the environmental problerns
caused by invasive e algae e, and the methods used to restore the natural habitats e in Crystal River and Kings Bay,
ments
Essay Response: (3 Paragraphs)
5
• Describe the environmental problem caused by invasive algae in these areas and the goals of the Save Crystal River
project.
• Explain the steps in the process used to correct the problem.
. Finally, conclude with why the information gathered during the Save Crystal River project is important to the
environment now and to future generations,
If someone can answer this fast I will mark as brainlist and give them 100 points plzz I need the answer fast and right!!
Answer:
PLS PLS PLS mark brainliest
Explanation:
The following are the environmental problems caused by the invasive algae which is known as Lyngbya.
A. It blocks the sunlight from reaching the water, thereby depriving the plants in the water from accessing it. So they won't be able to manufacture their foods and eventually die off.
B. The algae produce offensive odour like rotten egg , which drive people and other organisms away.
C. The algae prevent oxygen from entering the water, and prevent the resident organisms from making use of it, which leads to their death.
D. The algae also give off heat into the chilly spring waters.
In conclusion, the goals of the Crystal River project is to save the living organisms in the river from extinction and to make it a livable environment for them.
¿Crees que a más horas de sueño mayor descanso?
Answer:
La mayoría de los adultos necesitan entre 7 y 8 horas de sueño de buena calidad en un horario uniforme todas las noches.
Explanation:
During a chemical reaction, some substances are completely consumed while others my not be. What is the substance that is completely consumed in a chemical reaction?
Question 3 options:
reactant
product
a limiting reactant
Answer:
It is Limiting Reactant
Explanation:
Object A and Object B have the same volume of 10 cm³. Object A has a mass of 20 grams. Object B has a mass of 50 grams. Which object will have the greater density and why?
Answer:
Object B has greater density
desity A=20/10=2 g cm^-3 . density B=50/10=5 g cm^-3
the object that has greater mass has the greater density because the volume of the those two objects are same
Help please!!
What are the three criteria that determine if a wave is a sound wave?
Answer:
Wavelength, Amplitude, Time-Period, Frequency and Velocity or Speed.
Explanation:
Sound wave can be described by five characteristics: Wavelength, Amplitude, Time-Period, Frequency and Velocity or Speed. The minimum distance in which a sound wave repeats itself is called its wavelength. That is it is the length of one complete wave
Answer: Sound wave can be described by five characteristics: Wavelength, Amplitude, Time-Period, Frequency and Velocity or Speed.
Explanation:
The minimum distance in which a sound wave repeats itself is called its wavelength. That is it is the length of one complete wave.
The upper layer of soil consisting of rock particles, water, air, and organic matter is the
Answer: Bedrock
Explanation:
Bedrock is the solid layer of rock beneath the soil. Soil is a mixture of rock particles, minerals, decayed organic material, air, and water. The decayed organic material in soil is humus, a dark-colored substance that forms as plant and animal remains decay.
Which of the following is the unit of momentum
a) ms-1 b) Kg ms-1
c) Ns d) Kgms-2
Answer:
the answer is (b) Kg ms-1 .
what makes global winds curve rather than move in a straight line?
Answer:
because the Earth rotates, circulating air is deflected. Instead of circulating in a straight pattern, the air deflects toward the right in the Northern Hemisphere and toward the left in the Southern Hemisphere, resulting in curved paths. This deflection is called the Coriolis effect.
For every 120 joules of energy input a car wastes 85 joules , find the useful energy output of the car ?
Answer:
35 Joules
Explanation:
Applying
Input Energy(Q) = Useful energy output(U)+Wasted Energy(W)
Q = U+W.............................. Equation 1
Make U the subject of the equation
U = Q-W................... Equation 2
From the question,
Given: Q = 120 Joules, W = 85 Joules
Substitute these values into equation 2
U = 120-85
U = 35 Joules
The frequency range for a normal human ear is between 20 Hz and 20 000 Hz. Using 330 m/s as the speed of sound, a. Calculate the shortest wavelength of sound that can be heard: b. Calculate the longest wavelength of sound that can be heard:
Answer:
(a) 0.0165 m
(b) 16.5 m
Explanation:
Applying,
v = λf.................. Equation 1
Where v = velocity, f = frequency, λ = wave length.
make λ the subject of the equation
λ = v/f............. Equation 2
(a) Shortest wavelength (λ')
Given: f' = 20000 Hz, v = 330 m/s
Substitute these values into equation 2
λ' = 330/20000
λ' = 0.0165 m
(b) Longest wavelength (λ)
Given: v = 330 m/s, f = 20 Hz
Substitute these value into equation 2
λ = 330/20
λ = 16.5 m
which example would most likely decrease friction?
Answer:
using cleats other than gym shoes
Explanation:
the cleats hwve spikes and help gain speed
Which of these scenarios describes circular motion?
es )
A)
The moon orbiting the Earth
B)
A cannonball flying from a cannon
C)
A car moving along a straight track
D)
The pendulum of a grandfather clock
A)
The moon orbiting the Earth
26. A physical science student is performing a thermodynamics experiment in the school laboratory. She takes a 30.0 g ice cube at 0. °C and melts it to water in a beaker over a laboratory burner. She then heats the water to boiling at 100. °C. Finally she boils the water entirely to steam at 100. °C. How much thermal energy was gained by the water during this entire process?
Answer:
The thermal energy gained by the water during the entire process is 90,372 J
Explanation:
Given;
mass of the ice cube, m = 30 g
latent heat of fusion of ice, L = 334 J/g
specific heat capacity of water, C = 4.184 J/g⁰C
latent heat of vaporization of water, h = 2260 J/g
The thermal energy gained by the water during the entire process is calculated as;
[tex]Q_t = Q_{fusion-ice} \ + \ Q_{boil-water} \ + \ Q_{steam-vapor}[/tex]
The heat of fusion of the ice at 0⁰C is calculated as;
[tex]Q_{fusion} = mL = 30\ g \times 334 J/g = 10020 \ J[/tex]
The heat of capacity of the water from 0⁰C to 100 ⁰C
[tex]Q_{boil-water} = mc\Delta \theta = mc(100-0) = 30\ g \times 4.184\ J/g^0C \times 100\ ^0C = 12,552 \ J[/tex]
The heat of vaporization of the steam at 100⁰C is calculated as;
[tex]Q_{steam} = mh= 30 g \times 2260 \ J/g= 67,800 \ J[/tex]
The thermal energy gained by the water during the entire procees;
Qt = 10,020 J + 12,552 J + 67,800 J
= 90,372 J
Therefore, the thermal energy gained by the water during the entire process is 90,372 J
The information shows the masses after the compounds are balanced.
2MgO + 2Cl2 → 2MgCl2 + O2
85g + 156g → 188g + ?
If the following materials are used during the reaction of magnesium, oxygen, and chlorine, what mass oxygen would we expect to see after the reaction and why?
A.
53g of O2, because all mass must be conserved.
B.
241g of O2, because all mass must be conserved.
C.
42.5g of O2, because all mass must be conserved, it would be half of the compound MgO in the products.
D.
106g of O2, because all mass must be conserved, it would be double the compound MgO in the products.
Answer:
The information shows the masses after the compounds are balanced.
2MgO + 2Cl2 → 2MgCl2 + O2
85g + 156g → 188g + 53g
as total mass in reactant is equal to product.
A.
53g of O2, because all mass must be conserved.
A projectile is launched from the ground with an initial velocity of 12ms at an angle of 30° above the horizontal. The projectile lands on a hill 7.5m away. The height at which the projectile lands is most nearly
A- 1.78m
B- 3.10m
C- 5.34m
D- 6.68m
E- 12.0m
Answer:
A. 1.78 m
Explanation:
Given;
initial velocity of the, u = 12 m/s
angle of projection, θ = 30°
the range of the projectile, R = 7.5 m
To obtain the height through which the projectile lands, we must calculate the maximum height reached by the projectile.
[tex]H = \frac{u^2\ sin^2\theta}{2g} \\\\H = \frac{(12)^2\times (sin(30))^2}{2 \times 9.8} \\\\H = \frac{144 \times (0.5)^2}{19.6} \\\\H = 1.84 \ m[/tex]
Therefore, the height is most nearly 1.78 m
ABC
Question 18
A 110-kilogram bodybuilder and his 55-kilogram friend run up identical flights of stairs. The bodybuilder reaches the top
in 4.0 seconds while his friend takes 2.0 seconds. Compared to the power developed by the bodybuilder while running
up the stairs, the power developed by his friend is which of the following?
А
twice as much
B
the same
с
half as much
D
four times as much
Answer:
The answer is option C.Half as much
The correct answer is four times as much.
Let the friend's mass be m, then according to the question the bodybuilder's mass will be 2m.
Now they both cover the same distance but the bodybuilder takes 4s and his friend takes 2s. Hence, if the time taken by the friend is t then the bodybuilder takes 2t time.
That means if the velocity of the bodybuilder is v then the velocity of his friend will be 2v.
Now, Power is defined as the rate of work done.
P = W/t
and work done is the change in kinetic energy.
Now the power generated by the bodybuilder is:
[tex]P_{b}=\frac{\frac{1}{2}2mv^{2} }{2t} \\\\P_b=\frac{mv^2}{2t}[/tex] ............(1)
power generated by the friend is :
[tex]P_{f}=\frac{\frac{1}{2}m(2v)^{2} }{t} \\\\P_b=\frac{4mv^2}{2t}[/tex].............(2)
Comparing (1) and (2) we get:
The friend generates four times as much power as the bodybuilder.
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A boat moves through the water of a river at 10m/s relative to the water, regardless of the boat ‘s direction . If the water in the river is flowing at n1.50m/s , how long does it take the boat to make a round trip consisting of of 300m displacement downstream followed by a 300m displacement upstream?
Answer:
The appropriate solution is "61.37 s".
Explanation:
The given values are:
Boat moves,
= 10 m/s
Water flowing,
= 1.50 m/s
Displacement,
d = 300 m
Now,
The boat is travelling,
= [tex]10+1.50[/tex]
= [tex]11.5 \ m/s[/tex]
Travelling such distance for 300 m will be:
⇒ [tex]v = \frac{d}{t} \ sot \ t[/tex]
[tex]=\frac{d}{v}[/tex]
On putting the values, we get
[tex]=\frac{300}{11.5}[/tex]
[tex]=26.08 \ s[/tex]
Throughout the opposite direction, when the boat seems to be travelling then,
= [tex]10-1.50[/tex]
= [tex]8.5 \ m/s[/tex]
Travelling such distance for 300 m will be:
⇒ [tex]v=\frac{v}{t} \ sot \ t[/tex]
[tex]=\frac{d}{v}[/tex]
On putting the values, we get
[tex]=\frac{300}{8.5}[/tex]
[tex]=35.29 \ s[/tex]
hence,
The time taken by the boat will be:
= [tex]26.08+35.29[/tex]
= [tex]61.37 \ s[/tex]
(c) Another spring has a spring constant of 250 N/m.
Calculate the work done in stretching the spring by 0.30 m.
State the unit.
Use the equation
E = 12 x K x x2
See the picture and Anwser This
Answer:
20 m/s
Explanation:
Look at the time on the x-axis. Go up from 2 seconds until you reach a point. From that point go to the left and read from the y-axis.
A proton is released from rest in a uniform E – Field 8 x 104V/m directed alomg + ve x – axis, undergoes a displacement of 0. 5m in direction of field. Find: a) Change of potential for this displacement (A =» B)? B) Change of P.E for this displacement (A =» B)? C) The speed of proton after the displacement?
Answer:
a. -40 kV b. -6.408 fJ c. 2.77 × 10⁶ m/s
Explanation:
a) Change of potential for this displacement (A =» B)?
The potential energy change ΔV = -EΔx where E = electric field strength = 8 × 10⁴ V/m and Δx = displacement of charge = 0.5 m
So, ΔV = -EΔx
ΔV = -8 × 10⁴ V/m × 0.5 m
ΔV = -4 × 10⁴ V
ΔV = -40 × 10³ V
ΔV = -40 kV
B) Change of P.E for this displacement (A =» B)?
The change in potential energy ΔU = qΔV where q = proton charge = +1.602 × 10⁻¹⁹ C and ΔV = change in potential = -4 × 10⁴ V
So, ΔU = qΔV
ΔU = +1.602 × 10⁻¹⁹ C × -4 × 10⁴ V
ΔU = -6.408 × 10⁻¹⁵ J
ΔU = -6.408 fJ
C) The speed of proton after the displacement?
From the conservation of energy,
The electric potential energy change of the charge equals its kinetic energy change
ΔK + ΔU = 0
ΔK = -ΔU
ΔK = -(-6.408 × 10⁻¹⁵ J)
K₂ - K₁ = 6.408 × 10⁻¹⁵ J
where K₁ = initial kinetic energy of proton = 0 J (since it starts from rest)
K₂ = final kinetic energy of proton = 1/2mv² where m = mass of proton = 1.673 × 10⁻²⁷ kg and v = speed of proton
K₂ - K₁ = 6.408 × 10⁻¹⁵ J
1/2mv² - 0 = 6.408 × 10⁻¹⁵ J
1/2mv² = 6.408 × 10⁻¹⁵ J
v² = 2(6.408 × 10⁻¹⁵ J)/m
v = √[12.816 × 10⁻¹⁵ J)/1.673 × 10⁻²⁷ kg]
v = √[7.66 × 10¹² J/kg]
v = 2.77 × 10⁶ m/s
morse code and string phone cup
1.What was different about the two methods?
2.If your string phone stretched out one block long, which method do you think would be clearer?
3. If you had a Morse Code expert on both ends to act like a computer taking in information, would that make a difference?
Answer:
Following are the responses to the given question:
Explanation:
Following are the difference in the speed and accuracy:
The biggest difference was its tone between both the cup method as well as the Morse code. One should talk using cup system and sequence system and let its covering be understood in Morse code, just a series of beeps weren’t tangible... Secondly, a method of cup involves a range string. Rukun Negara is often distributed by cable, but this is a greater range. It reaches concurrently in those other areas.
In the case of using the string method for the block, its distance and stiffness of the string are limited and the barriers are eliminated. It will certainly be convenient and clearer if one utilizes Sign language.
If two experts are acting like such a machine on both sides, their information between both the 2 persons is smoother and quicker as they will not have to wait for data from a third person which may create another pause at the time.
Morse code is faster, eventually. For some very small periods when sensitive information is not transmitted, strings or cup methods must be reserved.
why stationary magnet inside a coil does not induce a electric current
Velocity is often described as speed with a __________.
Answer:
rate
Explanation:
Note that speed has no direction (it is a scalar) and the velocity at any instant is simply the speed value with a direction.