Answer:
Positive acceleration is when an object is increasing its velocity, speeding up.
Negative acceleration is when an object is decreasing its velocity, slowing down from it’s motion.
Zero acceleration is when an object is either at rest or moving without speeding up or slowing down, in a constant way.
A girl travels 50m in 12s and then another 30m in 5s .Calculate her average speed?
Answer:
4.71m/s
Explanation:
Average speed = Total distance travelled ÷ Total time taken.
80/17=4.71
4.71m/s
Answer:
Average speed = Total distance travelled ÷ Total time taken.In this question,
Total distance travelled = 50m + 30m= 80m.
Total time taken = 12s + 5s= 17s
So, Average speed would be 80 ÷ 17
= [tex]\frac{80}{17}[/tex]
= 4.71 m/s. or 4.71 meter per second.
1) Un cuerpo se mueve desacelerando a razón de 8m/s2, calcula: a) La velocidad que tenía 5 segundos antes de detenerse. b) La distancia recorrida los últimos 5 segundos de su trayectoria.
Answer:
Initial velocity (u) = 40 m/s
Distance travel in last 5 seconds = 100 m
Explanation:
Given:
Acceleration (a) = 8 m/s²
Final velocity (v) = 0 m/s
Find;
1] Initial velocity before 5 sec
2] Distance travel in last 5 seconds
Computation:
1] Initial velocity before 5 sec
v = u + at
0 = u + (-8)(5)
u - 40 = 0
Initial velocity (u) = 40 m/s
2] Distance travel in last 5 seconds
s = ut + (1/2)(a)(t²)
s = (40)(5) + (1/2)(-8)(5²)
s = 200 - 100
Distance travel in last 5 seconds = 100 m
Which statement is the best interpretation of the ray diagrem shown below
Answer:
B...................
Answer:
Option A is correct: "A concave mirror forming a larger, virtual image"
Explanation:
There are two types of mirror:
Concave (converging) mirrors: a concave mirror is a mirror that reflects the light inward
Convex (diverging) mirrors: a convex mirror is a mirror that reflects the light outward
The image formed by a mirror can also be of two types:
Real image: it is formed on the same side of the object, with respect to the mirror
Virtual image: it is formed on the opposite side of the object, with respect to the mirror
In the figure of this problem, we see that:
< The mirror reflects the light from the object inward --> so it is a concave mirror
< The image is formed on the other side of the mirror --> it is a virtual image
So the correct option is
A) A concave mirror forming a larger, virtual image
A swimmer is capable of swimming at 1.4m/s in still water. a. How far downstream will he land if he swims directly across a 180m wide river? b. How long will it take him to reach the other side.
Answer:
t = 180 / 1.4 = 129 sec (time to swim horizontally across river)
S = 129 sec * V where V is speed of current and S is the distance he will be carried downstream
The problem does not specify V the speed of the river
Answer:
Explanation:
From the given information:
a) the distance(D) showing how dar downstream he will land can be computed as follows:
Assuming the current of the river = 0.2 m/s
[tex]D = \dfrac{180 \ m \times 0.2 \ m/s}{1.4 \ m/s}[/tex]
D = 36 m ÷ 1.4
D = 25.71 m
The required time (t) to reach the other side is:
time (t) = 180 m/ 1.4 m/s
time (t) = 128.57 seconds
five scientist who travelled to space
Answer:
The Most Famous Astronomers of All Time. Karl Tate, SPACE.com. ...
Claudius Ptolemy. Bartolomeu Velho, Public Domain. ...
Nicolaus Copernicus. Public Domain. ...
Johannes Kepler. NASA Goddard Space Flight Center Sun-Earth Day. ...
Galileo Galilei. NASA
in a series circuit, how does the voltage supplied by the battery compare to the voltages on each load?
Answer:
In a series circuit, how does the voltage supplied by the battery compare to the voltage on each load? The voltage of the battery is equal to the voltage of each load added together. ... The voltage across the two resistors must both have the same voltage of the battery.
Explanation:
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Answer:
The voltage of the battery is equal to the voltage of each load added together. The voltage across the two resistors must both have the same voltage of the battery.
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Match the reactants with the products. zinc sulfate + copper aluminum chloride + copper copper oxide copper + water copper sulfate + oxygen
Answer:
The Reactants Products
Copper sulfate + zinc → Zinc sulfate + copper
aluminum + copper chloride → Aluminum chloride + Copper
Copper + Oxygen → Copper oxide
Explanation:
The Reactants Products
Copper sulfate + zinc Zinc sulfate + copper
aluminum + copper chloride Aluminum chloride + Copper
Copper + Oxygen Copper oxide
First reaction can be described as a single replacement reaction
Second reaction is also a single replacement reaction just like the first reaction
The third is a synthesis reaction ( i.e. reaction in which elements combine to form single compound )
calculate the volume of a ball having radius of 8 cm
Step-by-step explanation:
V = 2,143. 6 cm³ (rounded to one-decimal place) is the volume of a ball that has a radius of 8 cm.
Answer:
2143.57 cm^3
Explanation:
volume of a ball = 4/3 *π*r^3
= [tex]\frac{4}{3} *3.14 *8^{3}[/tex]
=[tex]\frac{4*3.14}{3} *512[/tex]
[tex]\frac{12.56}{3} *512[/tex]
=[tex]\frac{12.56*512}{3}[/tex]
=[tex]\frac{6430.72}{3}[/tex]
=2143.57
A chemical reaction is the change that takes place when ____ or more substances interact to form new substances.
Answer:
two or more substances
Explanation:
A chemical reaction can't take place if there is only one substance
Answer:
A chemical reaction is the change that takes place when two
or more substances interact to form new substances.
Explanation:
Chemical reactions occur when chemical bonds between atoms are formed or broken. The substances that go into a chemical reaction are called the reactants, and the substances produced at the end of the reaction are known as the products.
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A metal has a specific heat capacity of 360J/(kg°C).
An object made of this metal has a mass of 2.0kg.
What is the thermal capacity (heat capacity) of the object?
Answer:
Thermal capacity of the object = 720 j/°C
Explanation:
Given:
Specific heat capacity of metal = 360J/(kg°C)
Mass of given object = 2 kg
Find:
Thermal capacity of the object
Computation:
Thermal capacity = Specific heat x Mass
Thermal capacity of the object = Specific heat capacity of metal x Mass of given object
Thermal capacity of the object = 360 x 2
Thermal capacity of the object = 720 j/°C
A runner is traveling with an initial velocity of 0.3 m/s in the positive direction accelerates at a constant rate of 0.4m/s^2 for a time of 2 seconds. What is the velocity at the end of 2 seconds?
Answer:
1.1 m/s
Explanation:
Applying,
v = u+at.............. Equation 1
Where v = final velocity, u = initial velocity, a = acceleration, t = time.
From the question,
Given: u = 0.3 ms, a = 0.4 m/s², t = 2 seconds
Substitute these values into equation 1
v = 0.3+0.4(2)
v = 0.3+0.8
v = 1.1 m/s
Hence the velocity at the end of 2 seconds is 1.1 m/s
Answer pls…………………………
skater with a mass of 50.0 kg slides across an icy
pond with negligible friction. As he approaches a
friend, both he and his friend hold out their hands,
and the friend exerts a force in the direction oppo-
site to the skater's movement, which slows the skat-
er's speed from 2.0 m/s to 1.0 m/s. What is the
change in the skater's kinetic energy?
A. –25 J
C. – 100J
B. -75J
D. -150J
Answer:
B
Explanation:
Calculate the kinetic energy before and after they hold hands. Then, to find the change in kinetic energy simply subtract the final KE by initial KE.
if a train starts from rest and attains a velocity of 100m/s in 25 seconds. calculate the acceleration produced by the train.
A ball is thrown vertically up. If the ball reached at maximum height in 3s. Assume air resistance is negligible. What is the initial velocity of the ball. (Answer using a coordinate system where upwards is positive)
Answer:
Explanation:Gravitational force always acts on the ball in the downward direction, thus an acceleration due to gravity always point in the downward direction with a constant magnitude 10.6m/s
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The nucleus contains positively charged protons and uncharged neutrons . Protons and neutrons are collectively referred to as
A. nucleons
B. atoms
C. ions
d. molecules
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The density of aluminum is 2.7 g/cm^3. Which of the following statement is true?
A) 1 g of aluminium has a volume of 1 cm^3
B) 2.7 g of aluminium has a volume of 1 cm^3
C) 1 g of aluminium has a volume of 2.7 cm^3
D) 2 g of aluminium has a volume of 7 cm^3
Answer:
B) 2.7 g of aluminium has a volume of 1 cm^3
Explanation:
Density can be defined as mass all over the volume of an object.
Simply stated, density is mass per unit volume of an object.
Mathematically, density is given by the equation;
[tex]Density = \frac{mass}{volume}[/tex]
If the density of aluminum is 2.7 g/cm³, it simply means that 2.7 g of aluminium has a volume of 1 cm³
Check:
Given the following data;
Mass = 2.7 grams
Volume = 1 cm³
Substituting into the formula, we have;
[tex]Density = \frac{2.7}{1}[/tex]
Density = 2.7 g/cm³
To pop a balloon you stab it with a pencil. If the area of the pencil tip is .01 cm² and the pressure applied by the pencil to the balloon is 100 N/ cm², how hard (what force) must you push on the pencil to make the balloon pop?
Answer:
Push with force of 1N
Explanation:
I have explained in the paper.
Goodluck
You must push with 1 newton on the pencil to make the balloon pop.
What is force?The definition of force in physics is: The push or pull on a massed object changes its velocity.
An external force is an agent that has the power to alter the resting or moving condition of a body. It has a direction and a magnitude. The application of force is the location at which force is applied, and the direction in which the force is applied is known as the direction of the force.
A spring balance can be used to calculate the Force. Newton is the SI unit of force.
Applied pressure is = 100 N/cm².
Cross sectional area = 0.01 cm².
The required force = pressure × area
= 100 N/cm² × 0.01 cm²
= 1 Newton.
Hence, you must push with 1 newton on the pencil to make the balloon pop.
Learn more about force here:
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Jenny is doing her homework when Jenny writes, the pencil exerts a force of 5N on the paper. The area of the pencil in contact with the paper is 0.5mm2 calculate the pressure of the pencil in the paper give the unit
Answer:
here is your answer
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A football is projected at an angle of 30 from the ground with a n initial velocity of 10 m/s, take acceleration due to gravity is g= 10m/s2 .what is the time of flight
Answer: i dont know
Explanation:
Answer:
[tex]{ \bf \: time \: of \: flight : s = 0} \\ { \tt \: s \: is \: displacement} \\ \\ s = ut + \frac{1}{2} a {t}^{2} \\ 0 = u \sin( \theta) t - \frac{1}{2} g {t}^{2} \\ u \sin( \theta)t = \frac{1}{2} g {t}^{2} \\2 u \sin( \theta) = gt \\ { \boxed{ \tt{formular : time \: of \: flight = \frac{2u \sin( \theta) }{g} }}} \\ t = \frac{2 \times 10 \times \sin(30 \degree) }{10} \\ { \green{ \boxed{ \tt{ \bf{answer : { \tt{time \: of \: flight =1 \: second }}}}}}} \\ \\ { \tt{becker \: jnr}}[/tex]
Which of the following is not a true statement
Answer:
gadjgdasgdghgsdgd
Explanation:sorry need answer
Answer:
V * t = cm/sec * sec = cm
V * t should give distance as a result -
The other three fit the fundamental equations
A current of 17 A flows through a resistor of 10 2. What is the voltage
across the resistor
Which has greater kinetic energy, a car traveling at 40 mph or a half-as-massive car traveling at 80 mph?
a
-The 40 mph car
-The 80 mph car
-Both have the same kinetic energy
-Neither has kinetic energy
Answer:
The 80 mph car
Because the formula says 1/2 mass but for the velocity it is squared
Why do we see different phases of the lunar cycle?
A) As the moon rotates around its axis, different sides of it become visible.
B) as the earth rotates its axis, people can see different sides of the moon.
C) as earth revolves around the sun, the moon is cast into different shadows by earth.
D) as the moon revolves around earth, the different amounts of the sunlit side faces earth.
Answer: The answer is: D) as the moon revolves around earth, the different amounts of the sunlit side faces earth.
Explanation: I have my ways ;>
Have a great day!
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Which of these is untrue about ray diagrams?
A. The arrowheads show the direction of the light
B. Lines must always be straight
C. More arrowheads on lines mean a brighter light
Answer:
The untrue option is C: "More arrowheads on lines mean a brighter light"
Explanation:
Ray diagrams are used to show how the light behaves with things like mirrors or lenses. Where we only study how the direction of the light changes when it interacts with these objects.
The "light" is represented with arrows, where again, the only thing we care is the direction of the light, so the first statement is true, the arrowheads show the direction of the light, and only that.
The intensity of the light, in this context, has no effect on how light behaves, so there is not a necessity of representing the intensity of the light, thus, more arrowheads on lines do not mean a brighter light. It may only be used to represent changes in direction of the light.
Finally, we know that light travels in straight pats (the pats can be curved in some cases, like with large gravitational fields, but this is not the case of a ray diagram) so the lines that represent the light should always be straight, thus option B is also true.
The untrue option is C: "More arrowheads on lines mean a brighter light"
Một vật có khối lượng 2 kg rơi tự do xuống đất trong khoảng thời gian 0,5 s. Độ biến thiên động lượng của vật trong khoảng thời gian đó là bao nhiêu ? Cho g = 10 m/s2.
Answer: The change in momentum is +20 kg.m/s
Explanation:
To calculate the final velocity of object, we use the first equation of motion:
[tex]v=u+at[/tex]
where,
v = final velocity
u = initial velocity = 0 m/s
a = acceleration = [tex]10m/s^2[/tex]
t = time = 0.5 s
Putting values in above equation, we get:
[tex]v=0+(10\times 0.5)\\\\v=5m/s[/tex]
Momentum is defined as the product of the mass and velocity of an object. It is given by the equation:
[tex]p=mv[/tex]
where,
p = momentum
m = mass of object = 2 kg
Let the upward velocity be positive and the downward velocity be negative
When the object is dropped, the velocity is downward
v = -5m/s
Initial momentum = [tex]2kg\times (-5m/s)=-10kg.m/s[/tex]
When the object is bounced back, the velocity is upward
v = +5m/s
Final momentum = [tex]2kg\times (+5m/s)=10kg.m/s[/tex]
Change in momentum = Final - Inital
Change in momentum = [10 - (-10)] = +20 kg.m/s
Hence, the change in momentum is +20 kg.m/s
In this experiment, the ______ was intentionally manipulated. This was the independent variable.
A. fan speed
B. mass
C. acceleration
Answer:
Fan speed
Explanation:
because is the dependent variable
An aluminium cube of side 5cm and R.D 2.7 is suspended by a thread in alcohol of relative density 0.8o. Find the tension in thread.
Answer:
The tension in the thread is approximately 3.2103225 Newtons
Explanation:
The given parameters are;
The side length of the aluminum cube, s = 5 cm
The R.D. of aluminum = 2.7
The relative density of alcohol into which the aluminum cube is placed = 0.8
The volume of the aluminum cube, V = s³ = (5 cm)³ = 125 cm³
The mass of the aluminum cube, V = The volume of the cube
The mass of the aluminum cube, m = V × R.D. × Density of water
m₁ = 0.000125 × 2.7 × 970 = 0.327375 kg
The mass of the alcohol displaced, m₂ = 0.000125 × 0.8 × 970 = 0.097
The tension in the string, T = The apparent weight of the aluminum cube, Wₐ
∴ The tension in the thread, T = Wₐ = (m₁ - m₂) × g
Where;
g = The acceleration due to gravity ≈ 9.81 m/s²
∴ T ≈ (0.327375 - 0.000125) × 9.81 = 3.2103225
The tension in the thread, T ≈ 3.2103225 N.
Gold at 100.0°C is placed in 2.00×10^2 g of water at 20.0°C. The mixture reaches equilibrium at 21.2°C. the specific heat of gold is 0.129 (J/g°C) What is the mass of the gold? Specific heat of water is 4.18 (J/g°C) .
Answer:
there it is fella atleast i tried
The valid digits in a measurement are called _____ digits.
Answer:
Significant
Explanation:
As the word suggests, significant figures or digits are numbers that are valid in measurement.
Answer:
SIGNIFICANT DIGITS
Explanation:
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