Hannah comes to a rest in t = 0.4 s, so her acceleration is
a = (0 - 25 m/s) / (0.4 s) = -62.5 m/s²
(that is, the acceleration points in the direction opposing her movement forward as she brakes)
Then the force exerted on her by the seatbelt has magnitude
F = (65 kg) (62.5 m/s²) = 4062.5 N ≈ 4063 N
Two gliders collide on an air track. Glider 1 has a mass of 7.0 kg, and glider 2 has a mass of 4.0 kg. Before the collision, glider 1 had a velocity of 2.0 m/s, and glider 2 had a velocity of -5.0 m/s. If the collision is perfectly elastic, what is the total kinetic energy of both gliders after the collision?
A. -36.0 J
B. 36.0 J
C. 64.0 J
D. 128.0 J
Answer:
Its C
Explanation:
My teacher did it for me and it was right.
HELP ASAP!!! PLEASE!!
Answer:
Explanation:
The weaker force is pulling to direction East(450 newton)
the net force is (500-450=50 newton) and will move toward west ( in 500 newton direction)
is this right? plzz anwser soon
Answer:
yes
Explanation:
Answer:
y e p
Explanation:
A gold wire that is 1.8 mm in diameter and 15 cm long carries a current of 260 mA. How many electrons per second pass a given cross section of the wire
Answer: 162500000
Explanation:
given data:
wire diameter = 1.8mm
wire length = 15cm
current = 260mA.
electron charge e = [tex]1.6*10^{-19} C[/tex]
Solution:
[tex]I = \frac{q}{t}[/tex]
where:
[tex]I = current\\\\q = charge\\\\t = time \\\\q=It\\\\q= 260mt[/tex]
[tex]q=ne\\\\n = \frac{q}{e} \\\\n= \frac{260*10^{-3} t}{1.6*10^{-19} } \\\\n= 162500000t\\\\\frac{n}{t} = 162500000[/tex]
number of electrons per seconds would be 162500000
A race car accelerates from 0 m/s to 30.0 m/s with a displacement of
45.0 m. What is the vehicle's acceleration?
1. O 2.00 m/s2
2. 5.00 m/s2
3. 15.0 m/s2
4. 10.0 m/s2
Answer:
4. 10.0 m/s²
Explanation:
I) if initial velocity is 'v₀', the final velocity is 'v', the accelaration is 'a', the distance is 'L' and elapsed time if 't', then:
[tex]1. \ a=\frac{v-v_0}{t};[/tex]
[tex]2. \ L=\frac{at^2}{2}.[/tex]
II) using these two equations after substitution v₀=0; v=30 and L=45:
[tex]\left \{{{45 =\frac{at^2}{2}} \atop {a=\frac{30-0}{t} }} \right.[/tex]
[tex]\left \{ {{at^2=90} \atop {at=30}} \right. \ <=> \ \left \{ {{a=10} \atop {t=3}} \right.[/tex] [tex]=> \ a=10\frac{m}{s^2}[/tex]
1. Calculate the momentum of a 1.0 kg object moving with a velocity of +20 m/s.
2. What is the velocity of an object that has a momentum of -30 kg m/s and a mass of 3.0 kg?
3. Two objects have equal momentum but one has four times the mass of the other. What is the relationship between
their velocities?
4. Which answer below shows the correct units for momentum?
A. kg m/s
B. kg m/s?
C. kg m/s
D. kg s/m
5. Two bowling balls each have a mass of 4.0 kg
The red Bar is moving east 2.0 m/s. The blue ball is moving west at 1.0 m/s. Calculate the total momentum of the system.
Answer:
1)1*20=20
2)-30/3=- -10
3)velocity of the object 1=v1=4*V2
4) kg m/ s
5) momentum of the system= 12 kg m/ s
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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A 75 kg person climbs the 248 steps to the top of the Cape Hatteras lighthouse, a total climb of 59 m. How many Calories does he or she burn
Answer:
W = 41.45 Kcal
Explanation:
Given that,
The mass of a person, m = 75 kg
He climbs 248 steps to the top of the Cape Hatteras lighthouse, a total climb of 59 m.
We need to find how many calories does he or she burn.
Work done = Fd
d is displacement
⇒ W = 75 ×9.8 ×59
= 43365 J
Let the efficiency is 0.25.
[tex]W=\dfrac{43365}{0.25}\\\\=173460\ J\\\\\text{or}\\\\=41.45\ kcal[/tex]
So, 41.45 Kcal is burned by the person.
helpp please
ASAP...
Answer:
I believe it to be option A
Explanation:
What is the momentum of a 12 kg ball with velocity of 24 m/s?
Answer:
288 kg.m/sExplanation:
The momentum of an object can be found by using the formula
momentum = mass × velocity
From the question we have
momentum = 12 × 24
We have the final answer as
288 kg.m/sHope this helps you
A projectile is fired with a velocity of 8 m/s at an angle of 65º. What is the
vertical component of the velocity?
A. 6.5 m/s
B. 3.4 m/s
C. 10.2 m/s
D. 7.2 m/s
Answer:
i think its D
Explanation:
An inductor is connected to a 120-V, 60-Hz supply. The current in the circuit is 4.3A. What is the inductive reactance
Answer:
27.91ohms
Explanation:
From the question we are given the following
Voltage across the inductor VL = 120V
Current in the inductor I = 4.3A
Required
Inductive reactance XL
Using two formula
VL =IXL
XL = VL/I
XL = 120/4.3
XL = 27.91ohms
Hence the inductive reactance is 27.91ohms
How many types of rocks make up the Earth's crust?
Answer:
3, it's the igneous rock, sedimentary rock, and metamorphic rock i believe
Explanation:
Answer:
igneous, sedimentary, and metamorphic.
Explanation:
diffrence between:- movable pulley and fixed pully
Answer:
fixed pulley: A pulley system in which the pulley is attached to a fixed point and the rope is attached to the object. ... movable pulley: A pulley system in which the pulley is attached to the object; one end of the rope is attached to a fixed point and the other end of the rope is free.
Explanation:
If a small motor does 520 J of work to move a toy car 260 m, what force does the engine exert on the car?
Answer:
2 NExplanation:
The force engine exert on the car can be found by using the formula
[tex]f = \frac{w}{d} \\ [/tex]
w is the workdone
d is the distance
From the question we have
[tex]f = \frac{520}{260} = 2 \\ [/tex]
We have the final answer as
2 NHope this helps you
Can someone please explain this?
Explanation:
u = Initial velocity = 20m/s
v = Final velocity = 0m/s
a = Acceleration = -5m/s²
We wish to find s, the displacement of the car.
Using Kinematics, we have v² = u² + 2as.
Therefore (0)² = (20)² + 2(-5)s, and s = 40m.
Helppp!!
Research indicates that teenagers tend to become impaired by alcohol
adults.
A. faster than
B. slower than
C. at the same rate as
Answer:
A faster because teens what to drink it more when. they see there parents do it
Research indicates that teenagers have a faster tendency compared to adults in these case.
What are the process to encourage good behavior in pre-teens and teenagers?Good behavior in pre-teens and teenagers starts with positive communication and warm relationships. This lays the foundation for guiding your child’s behavior in a positive way.
Here are some practical tips for putting this positive approach into action.
Active listening entails paying close attention to your child's words and body language while they are being said. This enables you to pay attention to your child's feelings and thoughts. Additionally, it demonstrates to your child your concern and interest in them.Clear expectations concerning behaviour are outlined in family rules. Include every member of the family in the rule-setting talks, if you can. Maintaining good rules is important. For instance, you might say, "We treat each other with respect," rather than, "Don't be disrespectful."Find more about teenagers, refer the link:
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A ball falls through the air at terminal velocity. Which of the following are forces that should be included in a free body
diagram? (select all that apply)
air resistance
force of motion
gravity
force of fall
Answer:
air resistance and gravity.
Explanation:
When the ball is falling down at terminal velocity, the velocity is constant.
This means that the net force acting on the ball will be zero (there is no acceleration)
In this situation, there are only two forces that can act on the ball.
The gravitational force, that pulls the ball down.
The air resistance which opposes to the movement of the ball and increases in magnitude as the velocity of the ball increases.
Then there is a point where the velocity of the ball is such that the air resistance is equal in magnitude to the acceleration, and then the net force becomes zero.
Then the two forces that need to be included in this diagram are the air resistance and gravity.
What are your thoughts about Russia getting banned from the 2020 Olympics and 2022 World cup?
The wavelength of a particular color of violet light is 417 nm. The energy of this wavelength of light is
Answer:
E = 4.7 x [tex]10^{-19}[/tex] Joules
Explanation:
Solution:
The wavelength of a particular color of violet light = 417 nm
What is the energy = ?
In order to calculate energy, we will use the following formula:
E = hf
where, f = frequency = 1/wavelength = c/λ
where c = speed of light = 299 792 458 m / s or 3 x [tex]10^{8}[/tex] m/s
where h = Plank's constant = 6.62x [tex]10^{-34}[/tex] [tex]m^{2}[/tex] kg / s
So,
λ = 417 nm
1 nm = [tex]10^{-9}[/tex] m
so,
λ = 417 x [tex]10^{-9}[/tex] m
Now, just plug in the values to calculate the energy of this wavelength of light.
E = hc/λ
E = ( 6.62x [tex]10^{-34}[/tex] ) (299 792 458) / (417 x [tex]10^{-9}[/tex] )
E = 0.047 x[tex]10^{-17}[/tex]
E = 4.7 x [tex]10^{-19}[/tex] Joules
Calculate the heat energy needed to change the temperature of 2 kg of copper from 10°C to 110°C.
If you could show your process and equations used, that would be very helpful! Thanks!
Answer:
77000 J
Explanation:
Formula for the heat energy is;
Q = m•c•Δt
We are given;
mass; m = 2 kg
Change in temperature; Δt = 110 - 10 = 100 °C
From online values, specific heat capacity of copper is; c = 385 J/kg.°C
Thus;
Q = 2 × 100 × 385
Q = 77000 J
Answer:
heat = 20 Kcal
Explanation:
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.
when a man throws a stone in the direction of maximum range the stone rises to a height of 20m . what is the range and how long is the stone in air
Answer:
50m
Explanation:im just smart thank me later
The range is 80 meter and the stone is 4.04 second in air.
What is projectile?When a particle is hurled obliquely near the surface of the earth, it travels along a curved path while accelerating continuously in the direction of the planet's center (we assume the particle stays close to the surface of the globe). Such a particle's motion is known as projectile motion, and its route is referred to as a projectile.
Given that: maximum height obtained by the projectile; H = 20 m.
Let initial velocity = u
For maximum range:
H = u²/4g
u = √(4gH) = 28 m/s
and the range of the projectile = u²/g = 4H = 4 ×20 m = 80 m.
Total time of flight = √2· u/g = √2 ×28/9.8 = 4.04 second.
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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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A dynamite blast blows a heavy rock straight up from the ground with a launch velocity of 160ft/sec. a) Write the height function.
Answer:
y = 160t - 16t²
Explanation:
Using y = ut -1/2gt² where y = height of heavy rock above the ground, u = initial launch velocity of rock = 160 ft/s, g = acceleration due to gravity = 32 ft/s² and t = time.
So, substituting the values of the variables into y, we have
y = (160 ft/s)t -1/2 × 32 ft/s² × t²
y = (160 ft/s)t - (16 ft/s²)t²
y = 160t - 16t²
So, the height function is y = 160t - 16t²
You drop a coin off of a building and in lands flat on the ground. It hits with a pressure of 200N/m2. It has a weight of 0.1N. What is the area of the coin?
Answer:
5×10¯⁴ m².
Explanation:
From the question given above, the following data were obtained:
Pressure (P) = 200 N/m²
Weight = Force (F) = 0.1 N
Area (A) =?
Pressure, force and area are related by the following equation:
Pressure (P) = Force (F) / Area (A)
P = F / A
With the above formula, we can obtain the area of the coin as follow:
Pressure (P) = 200 N/m²
Weight = Force (F) = 0.1 N
Area (A) =?
P = F / A
200 = 0.1 / A
Cross multiply
200 × A = 0.1
Divide both side by 200
A = 0.1 / 200
A = 5×10¯⁴ m²
Thus, the area of the coin is 5×10¯⁴ m².
3. Missy Diwater, the former platform diver for the Ringling Brother's Circus, had a kinetic energy of 12,000 ) just prior to hitting the bucket of water. If Missy's mass is 40 kg, then what is her speed?
Answer:
v = 24.49[m/s]
Explanation:
We must remember that kinetic energy can be calculated by means of a mathematical expression, which relates kinetic energy to mass and velocity
[tex]E_{kin}=\frac{1}{2}*m*v^{2} \\[/tex]
where:
Ekin = kinetic energy = 12000 [J]
m = mass = 40 [kg]
v = velocity [m/s]
[tex]12000=\frac{1}{2} *40*v^{2}\\24000=40*v^{2}\\600=v^{2}\\v=\sqrt{600}\\v=24.49[m/s][/tex]
what must be photographed with an impression before it is moved or cast ?
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
PLEASE HELP ASAP
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2. What are three crucial pieces of evidence that supports the claim for the Big Bang theory. Include a piece of evidence that relates each of the following:
a. Light spectra
b. Motion of distant galaxies
c. Composition of matter in the universe
3. Explain how or why each piece of evidence supports the claim made in Big Bang theory.
Answer:
The evidence that the universe is expanding comes with something called the red-shift of light. Light travels to Earth from other galaxies. As the light from that galaxy gets closer to Earth, the distance between Earth and the galaxy increases, which causes the wavelength of that light to get longer. Distant galaxies are getting further away hinting at a point of origin. The composition of all observed matter in this universe points at a common origin point for all matter in the universe.
The three crucial evidences that supported the Big Bang theory are the CMB or cosmic microwave background, the expanding universe, the abundance of elements in the universe.
What is Big Bang theory ?Big Bang theory is one of the important theory scientists used in earliest to describe the origin of universe and the phenomenon of evolution.
Here,
2. The Big Bang theory described the origin of universe as an expansion from an atmosphere of high density and extreme temperature which lead to a huge explosion of matter known as the 'Big Bang' and thus creation of the universe.
The three crucial evidences that supported the Big Bang theory are:
The CMB or cosmic microwave background, the expanding universe, the abundance of elements in the universe.
3.(a) Light spectra was an important factor that supported the Big Bang theory mainly by the phenomenon called Doppler shift. Doppler shift occurs when stars move away, they get shifted to longer wavelength. This phenomenon is called red-shift or Doppler's Red shift. This was applicable in the case of Big Bang theory such that the theory claimed that, as a result of explosion which is the Big Bang, the material particles move away. This was similar to the red shift.
(b) The motion of distant galaxies was an evidence of the expansion of universe and soo the Big Bang theory. It was explained in such a way that, as the galaxies move away from us, it shows the more expansion of universe and the time duration since the origin of universe.
(c) The composition of matter in the universe was an important evidence that supported the Big Bang theory. The composition of universe that there is high abundance of hydrogen and helium in the atmosphere was claimed by the Big Bang theory.
Hence,
The three crucial evidences that supported the Big Bang theory are the CMB or cosmic microwave background, the expanding universe, the abundance of elements in the universe.
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