Answer:
s = 2.79 m
Explanation:
Given that,
A ball have a speed of 7.4 m/s just before it hits the ground.
Initial velocity of the ball was 0 (at rest)
We need to find the height from where the ball was dropped. It means we need to find the distance covered by it. Let it is h.
Using the third equation of motion to find it as follows :
[tex]v^2-u^2=2as\\\\s=\dfrac{v^2}{2g}\\\\s=\dfrac{(7.4)^2}{2\times 9.8}\\\\s=2.79\ m[/tex]
So, the ball is dropped from a height of 2.79 m.
The height from which you would have to drop a ball so that it would have a speed of 7.4 m/s just before it hits the ground is 2.79m
Equation of motionsAccording to the third equation of motion;
[tex]v^2=u^2+2as[/tex]
where;
v is the final velocity = 7.4m/s
Initial velocity = 0m/s
s is the distance
a = g= 9.8m/s²
Substitute the values into the formula to have:
[tex]7.4^2=0^2+2(9.8)s\\54.76 + 19.6s\\s=\frac{54.76}{19.6}\\ s=2.79m[/tex]
Hence the height from which you would have to drop a ball so that it would have a speed of 7.4 m/s just before it hits the ground is 2.79m
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A satellite of mass m orbits a moon of mass M in uniform circular motion with a constant tangential speed of v. The gravitational field strength at a distance R from the center of moon is gR. The satellite is moved to a new circular orbit that is 2R from the center of the moon. What is the gravitational field strength of the moon at this new distance
The satellite is moved to a new circular orbit that is 2R from the center of the moon, then the gravitational field strength of the moon at this new distance would be one-fourth of the initial gravitational field.
What is gravity?It can be defined as the force by which a body attracts another body toward its center as the result of the gravitational pull of one body and another.
As given in the problem A satellite of mass m orbits a moon of mass M in a uniform circular motion with a constant tangential speed of v. The gravitational field strength at a distance R from the center of the moon is gR. The satellite is moved to a new circular orbit that is 2R from the center of the moon.
The gravitational field strength is inversely proportional to the square of the distance from the center of the planet.
Thus, the gravitational field strength of the moon at this new distance would be one-fourth of the initial gravitational field.
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The least count of stopwatch is 0.2s.The time of 20 oscillations of a pendulum was measured to be 25s.Find the percentage error in the measurement of time
Answer:
0.8%
Explanation:
We are given;
Number of oscillations; n = 20
Time taken; t = 25 s
Formula for period of oscillation;
T = t/n = 25/20 = 1.25 s
We are told that the least count is 0.2 s. Thus, error is; ΔT = 0.2 s
percentage error in the measurement of time is given by;
(0.2/(20 × 1.25)) × 100% = 0.8%
The plate area is doubled, and the plate separation is reduced to half its initial separation. What is the new charge on the negative plate
Answer:
Q = 4 Q₀
Explanation:
This is an exercise on capacitors, where the capacitance is
C = [tex]\epsilon_{o} \ \frac{A}{d}[/tex]
if we apply the given conditions
C = \epsilon_{o} \ \frac{2A}{0.5d}
C = 4 \epsilon_{o} \ \frac{A}{d}
let's call the capacitance Co with the initial values
C₀ = \epsilon_{o} \ \frac{A}{d}
C = 4 C₀
The charge on each plate of a capacitor is
Q = C ΔV
If the potential difference is maintained, the new charge is
Q = 4 C₀ ΔV
let's call
Q₀ = C₀ ΔV
we substitute
Q = 4 Q₀
Select the correct answer.
What type of motion means to bounce or spring back?
Spin
Rotate
Rebound
Speed
Answer:
Rebound
Explanation:
Answer:
Rebound is your answer
Explanation:
To rebound is to bounce or
spring back after coming into
contact with another object.
Examples:
Rebound
• A basketball rebounds off the
backboard.
• A hockey puck rebounds off
the wall.
A 420 g soccer ball is kicked into the air with an initial velocity of 30 m/s. How much kinetic energy does the soccer ball have?
Answer:189000J
Explanation:KE=1/2mv^2
1/2(420g)(30m/s)^2
=189000J
( I will give a brainliest )
What must be changed, temperature or heat energy, during condensation?
Answer:
The answer is temperature lol
Explanation:
:)
let's say you hypothetically ran over someone with your car, and they are now under your car in between the front wheels and the back wheels, right, and they're stuck as in can't breathe type stuck, right, do you keep driving so they can breathe or do you let them chill under your car?
just curious...
question: is this actually hypothetical?
Explanation:
also just leave the car there go get some McDonald's or sum and come back and if they're still breathing then go ahead and move the car .
Answer:
the same thing the last guy said
a ball of diameter 10 cm and mass 10 grams is dropped in a container of water. the cross sectional area of the container is 100 cm2.. what is the change in the height of the water column
Answer:
h = 9.83 cm
Explanation:
Let's analyze this interesting exercise a bit, let's start by comparing the density of the ball with that of water
let's reduce the magnitudes to the SI system
r = 10 cm = 0.10 m
m = 10 g = 0.010 kg
A = 100 cm² = 0.01 m²
the definition of density is
ρ = m / V
the volume of a sphere
V = [tex]\frac{4}{3} \ \pi r^{3}[/tex]
V = [tex]\frac{4}{3}[/tex] π 0.1³
V = 4.189 10⁻³ m³
let's calculate the density of the ball
ρ = [tex]\frac{0.010}{4.189 \ 10^{-3} }[/tex]
ρ = 2.387 kg / m³
the tabulated density of water is
ρ_water = 997 kg / m³
we can see that the density of the body is less than the density of water. Consequently the body floats in the water, therefore the water level that rises corresponds to the submerged part of the body. Let's write the equilibrium equation
B - W = 0
B = W
where B is the thrust that is given by Archimedes' principle
ρ_liquid g V_submerged = m g
V_submerged = m / ρ_liquid
we calculate
V _submerged = 0.10 9.8 / 997
V_submerged = 9.83 10⁻⁴ m³
The volume increassed of the water container
V = A h
h = V / A
let's calculate
h = 9.83 10⁻⁴ / 0.01
h = 0.0983 m
this is equal to h = 9.83 cm
What are forces like in a collision?
Answer:
equal in magnitude and opposite in direction.
Explanation:
I don't have 1 I just knew -_('-')_-
Optimus Prime is flying straight up at 24 m/s when he accidentally drops his mega-ray blaster and it falls 94 m to the ground below. Calculate how long it takes for his mega-ray blaster to hit the ground.
Answer:
The time it will take the mega-ray blaster to hit the ground is 2.57 s.
Explanation:
Given;
initial velocity of Optimus Prime, u = 24 m/s
height of fall of the mega-ray blaster, h = 94 m
The time of fall of the mega-ray blaster is calculated using the following kinematic equation;
[tex]h = ut + \frac{1}{2}gt^2\\\\94 = 24t + \frac{1}{2}(9.8)t^2\\\\94 = 24t + 4.9t^2\\\\4.9t^2 +24t -94 = 0\\\\Use \ formula \ method \ to \ solve \ for \ "t"\\\\a = 4.9 , b = 24, c = -94\\\\t = \frac{-b \ +/- \ \sqrt{b^2 -4ac} }{2a} \\\\t = \frac{-24 \ +/- \ \sqrt{(24)^2 -4(-94 \times4.9)} }{2(4.9)} \\\\t = \frac{-24 \ +/- \ \sqrt{2418.4} }{9.8}\\\\t = \frac{-24 \ +/- \ 49.177 }{9.8}\\\\t = \frac{-24 \ +\ 49.177 }{9.8} \ \ or \ \ t = \frac{-24 \ -\ 49.177 }{9.8} \\\\[/tex]
[tex]t = 2.57 \ s \ \ or \ \ t = -7.47 \ s[/tex]
t = 2.57 s
Therefore, the time it will take the mega-ray blaster to hit the ground is 2.57 s.
Which type of telescope is best used to detect distant planets?
how are hydrosphere, atmosphere, Biosphere, and Biosphere connected to one another
Explanation:
Such spheres are intimately connected. Many animals (biosphere), for example, migrate through to the sky, while groundwater (hydrosphere) also flows through the ground (lithosphere). The domains are actually so closely related that a shift in one globe always results in a shift in one or both of some other spheres.
A(n) 636 kg elevator starts from rest. It moves upward for 4.5 s with a constant acceleration until it reaches its cruising speed of 2.05 m/s. The acceleration of gravity is 9.8 m/s 2 . Find the average power delivered by the elevator motor during this period. Answer in units of kW.
Answer:
The average power delivered by the elevator motor during this period is 6.686 kW.
Explanation:
Given;
mass of the elevator, m = 636 kg
initial speed of the elevator, u = 0
time of motion, t = 4.5 s
final speed of the elevator, v = 2.05 m/s
The upward force of the elevator is calculated as;
F = m(a + g)
where;
m is mass of the elevator
a is the constant acceleration of the elevator
g is acceleration due to gravity = 9.8 m/s²
[tex]a = \frac{v-u}{t} \\\\a = \frac{2.05 -0}{4.5} \\\\a = 0.456 \ m/s^2[/tex]
F = (636)(0.456 + 9.8)
F = (636)(10.256)
F = 6522.816 N
The average power delivered by the elevator is calculated as;
[tex]P_{avg} = \frac{1}{2} (Fv)\\\\P_{avg} = \frac{1}{2} (6522.816 \ \times \ 2.05)\\\\P_{avg} = 6685.89 \ W\\\\P_{avg} = 6.68589 \ kW\\\\P_{avg} = 6.686 \ k W[/tex]
Therefore, the average power delivered by the elevator motor during this period is 6.686 kW.
Select the correct answer.
Which of these factors will increase the speed of a sound wave in the air?
A. slowing down the movement of particles in the air
B. raising the temperature of the air
C. removing particles form the air
D. decreasing the kinetic energy of the air
E. stopping particle collisions in the air
Answer:
B
Explanation:
But molecules at a higher temperature have more energy.
Answer: B. Raising the temperature of the air
Two asteroids begin to gravitationally attract one another. If one asteroid has twice the mass of the other, which one experiences the greater force
Answer:
F = G \frac{2 m^{2} }{r^{2} }
action and reaction forces with the same magnitude, but in the opposite direction, one applied to each body.
Explanation:
The force between the asteroids is given by the law of universal gravitation
F = G m₁ m₂ / r²
in this case they give us the mass of each asteroid
m₁ = m
m₂ = 2m
we substitute
F = G m 2m / r²
F = G 2 m² / r²
[tex]F = G \frac{2 m^{2} }{r^{2} }[/tex]
Let's analyze this expression, this is the force that one asteroid exerts on the other, therefore there are two forces, one applied to each asteroid, as the order of the products does not affect the result, the magnitude of the force is the same on each asteroid.
These are action and reaction forces with the same magnitude, but in the opposite direction, one applied to each body.
Consequently the two asteroid experiences the same magnitude of force
The Sun's energy comes from which nuclear reaction? O A. Two nuclei joining to form a larger nucleus OB. Two nuclei giving off alpha particles OC. A nucleus splitting to form two or more smaller nuclei D. A nucleus giving off a positron
Answer:
Nuclear Fusion reactions power the Sun and other stars. In a fusion reaction, two light nuclei merge to form a single heavier nucleus. The process releases energy because the total mass of the resulting single nucleus is less than the mass of the two original nuclei.
Explanation:
The sun's energy comes in the form of a nuclear reaction due to the Two nuclei joining to form a larger nucleus. Thus option A is correct.
What is nuclear fusion?A nuclear fusion is a reaction in which 2 or more atomic nuclei combine to form one or more atomic nuclei and is manifested by the release or the absorber of energy.
This is due to the differeces in the nuclear binding energy due to the force of nuclei before and after the reaction. The process releases energy as single declines less than the mass of the original nuclei.
Find out more information about the nuclear reaction.
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which sun's energy comes from which nuclear reaction
Answer:
the nuclear fusion process
Explanation:
:)
Answer:
nuclear fusion (not fission)
Explanation:
a p e x :))
HELP ASAP!
Everything on screenshot.
Answer:
11. D
12. A
13. B
Explanation:
please help thank you
which of the following statements BEST describes the difference between an atom and an ion ?
Answer:
well the correct answer is
d. An atom contains equal numbers of protons and electrons whereas an ion contains unequal numbers of protons and electrons .Explanation:
A charged atom is known as an ion, well it can be negative as well as positive charge.
if atom has more protons than electrons then it get positively charged and known as cationif the atom has more electrons that the number of protons then the atom get negatively charged and known as anionWILL GIVE BRAINLIEST TO THE CORRECT ANSWER
PLEASE HELP THIS IS DUE TODAY!
If a 1000kg car is accelerating at 3m/s/s for 4 seconds how far will it travel
If at some point in time an object has zero velocity and zero acceleration, what does that mean about its motion at the next instant
Answer:
Explanation:
Usually, when an object possesses 0 velocity, then the object is expected to be at rest. But like the popular saying, there's always an exception to every rule. There exists cases in which an object isn't at rest, but possesses 0 speed or velocity. Since acceleration is the rate of change of velocity with time, the acceleration becomes negative, instead of positive.
Again, when the acceleration becomes zero, it means that the object isn't moving or it has no speed. And thus, the body is at rest. Every moving body as an acceleration, either positive, or negative. Zero acceleration means the object is at rest, and not moving at all.
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At any point in time, when
when the acceleration becomes zero, it means that the object isn't moving or it has no speed. And thus, the body is at rest.
What is acceleration?Acceleration is defined as the change of the velocity with the time. Acceleration is a vector quantity and is defined by both the magnitude and the direction
when the acceleration becomes zero, it means that the object isn't moving or it has no speed. And thus, the body is at rest. Every moving body as an acceleration, either positive, or negative. Zero acceleration means the object is at rest, and not moving at all.
Now If an object is moving with an acceleration that causes its speed to be reduced, there will be a moment in which it reaches v = 0, but this doesn't necessarily mean that the acceleration isn't acting anymore. If the object continues its movement with the same acceleration, it's velocity will become negative.
If you throw an object in the air with a certain velocity, it will move vertically, reducing its velocity in a 9,8 rate (which is the acceleration caused by gravity). At a certain point, the object will reach its maximum height, and will start to fall. In the exact moment that it reaches the maximum height, before it starts falling, its velocity is zero, but gravity is still acting on the object (this is the reason why it starts falling instead of just being stopped at that point). Therefore, at that point, the object has zero velocity but an acceleration of 9,8 .
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Two identical plastic cups contain the same amount of water at two different temperatures, as shown to the left. Both cups are placed in a room at 25° Celsius. At the time cups were placed in the room, in which cup do the water molecules have higher average kinetic energy? ( Cup 1 © Cup 2
Answer:
the molecules will begin to move slowly and will turn to ice
Explanation:
hope this was good or not not sure if am right but yeah
Two ice skaters stand together. They push off and travel directly away from each other, the boy with a velocity of v = +0.35 m/s. If the boy weighs 745N and the girl 477 N, what is the girl's velocity after they push off? ( Consider the ice to be frictionless)_____m/s
Answer:
-0.55m/s
Explanation:
Given that: For the boy
Weight = 745N
Velocity = +0.35 m/s
Mass of the boy = ?
g = 9.81m/s^2
W = mg
745 = m×9.81
m = 75.94kg
For the girl
Given that:
Weight = 477 N
g = 9.81m/s^2
m = ?
W = mg
477 = m×9.81m/s^2
m = 48.62kg
To solve for the v of the girl, the two has to add up
48.62kg×v + 75.94kg×+0.35 m/s = 0
48.62v + 26.579 = 0
48.62v = - 26.579
v = -26.579/48.62
v = -0.5466
v = -0.55m/s
Hence, the velocity of the girl is -0.55m/s.
The negative sign is as a result of the two of them moving is opposite direction.
A volleyball experiences 494 Ns of impulse over a time period of 7 seconds. What was the magnitude of the force that acted on the volleyball during this time period?
Answer:
70.6N
Explanation:
Given parameters:
Impulse = 494Ns
Time = 7s
Unknown:
Force applied = ?
Solution:
To solve this problem, we use the formula of impulse;
Impulse = Force x time
Now insert the parameters and solve;
494 = Force x 7
Force = [tex]\frac{494}{7}[/tex]
Force = 70.6N
two cars with initial speed 2v and v, lock their brakes and skid to a stop. what is the ratio of the distance travelled
Answer:
4:1
Explanation:
Given that the initial speed of the first car, u = 2v while the initial speed of the second car, u = v. To find the distance travelled, we are going to apply one of the equations of motion. The equation chosen is
v² = u² - 2as, where
s = the distance needed
a = acceleration due to gravity
u = initial velocity which is v & 2v
v = final velocity which is 0
For the first car with initial velocity, 2v, on substituting into the equation, we have
v² = u² - 2as(1)
0 = 4v - 2as(1)
4v = 2as(1)
2v = as(1), making s(1) subject of formula we have
s(1) = 2v/a
Taking the second car, we have u = v
v² = u² - 2as(2)
0 = v - 2as(2)
v = 2as(2), making s(2) subject of formula, we have
s(2) = v/2a
Not, ratio of s1 : s2 =
2v/a : v/2a
s1/s2 = 2v/a ÷ v/2a
s1/s2 = 2v/a * 2a/v
s1/s2 = 4av/av
s1/s2 = 4/1
Therefore, the ratio of the first car to the second car is 4:1
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How will a metal container full of hot water in vaccum lose heat?
1. A low frequency will have a wavelength?
Answer:
There are many kinds of waves all around us. There are waves in the ocean and in lakes. Did you also know that there are also waves in the air? Sound travels through the air in waves and light is made up of waves of electromagnetic energy.
The wavelength of a wave describes how long the wave is. The distance from the "crest" (top) of one wave to the crest of the next wave is the wavelength. Alternately, we can measure from the "trough" (bottom) of one wave to the trough of the next wave and get the same value for the wavelength.
The frequency of a wave is inversely proportional to its wavelength. That means that waves with a high frequency have a short wavelength, while waves with a low frequency have a longer wavelength.
Light waves have very, very short wavelengths. Red light waves have wavelengths around 700 nanometers (nm), while blue and purple light have even shorter waves with wavelengths around 400 or 500 nm. Some radio waves, another type of electromagnetic radiation, have much longer waves than light, with wavelengths ranging from millimeters to kilometers.
Sound waves traveling through air have wavelengths from millimeters to meters. Low-pitch bass notes that humans can barely hear have huge wavelengths around 17 meters and frequencies around 20 hertz (Hz). Extremely high-pitched sounds that are on the other edge of the range that humans can hear have smaller wavelengths around 17 mm and frequencies around 20 kHz (kilohertz, or thousands of Hertz).
Explanation:
Explanation:
Hope This Helped U
Brqinliest
A different bullet has a mass of 0.09 kg. Starting from rest, after its gun's trigger is pulled, a constant force acts on the bullet for the next 0.025 seconds until the bullet leaves the barrel of the gun with a speed of 1,346 m/s.
What force acts on this bullet?
The force acts on this bullet : 4.8456 N
Further explanationGiven
m=0.09 kg
Δt=0.025 s
vo=0(from rest)
vt=1.346 m/s
Required
Force
Solution
Impulse is a change in momentum
I=ΔP
F.Δt=m(vt-vo)
Input the value
F x 0.025 = 0.09(1.346-0)
F=4.8456 N
What is the relationship between force and momentum?
A. A force will always increase momentum
B. A force acting for a certain time results in a change in momentum
C. There is no relationship
D. It depends on the kind of force
Answer:
Explanation:
B
Help! Help!
___ are a primary way to discourage drinking and driving.
A. High prices for alcohol
B. Scare tactics
C. Laws
Answer:
Laws
Explanation:
Laws are a primary way discourage drinking and driving
A primary way to discourage drinking and driving is Law.
What is drinking and driving?The person who takes in alcohol and then drives on the road. This is strictly prohibited.
Laws against the 'drinking and driving' will make people get scared of getting charged or sentenced to jail for some years. Lot of accidents have caused when there were no laws against the action.
Thus, Laws are a primary way to discourage drinking and driving.
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