The total time for the whole journey = 7 hours
Distance = Speed x time
Distance traveled for the first 3 hours
time = 3 hours
speed = 60 km/h
Distance = 60 x 3
Distance = 180 km
180 km was traveled for the first three hours
Total distance traveled = 460 km
Distance traveled at an average speed of 70 km/h = 460 - 180
Distance traveled at an average speed of 70 km/h = 280 km
Speed = Distance / time
70 = 280 / time
time = 280 / 70
time = 4 hours
Mr. Ben traveled 3 hours at an average speed of 60 km/h, he traveled 4 hours at an average speed of 70 km/h.
The total time for the whole journey = 3 hours + 4 hours
The total time for the whole journey = 7 hours
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Please Help! 25 BRAIN POINTS
Romeo (m = 60 kg)runs North towards Juliet (m = 45 kg) at a speed of 1.5 m/s. Juliet runs South towards Romeo at a speed of 2.2 m/s. The 2 collide (epic hug) in a head-on perfectly elastic collision. Find the velocity of the star-crossed lovers immediately after the collision.
Answer: V' = 1.514m/s
Explanation: Given the Impulse-Momentum Theorum, this is a description of an INELASTIC Collision. When you hug, you stick, making it inelastic.
Formula: m1xV1+m2xV2= pTotal, or total momentum
m1=60kg
V1=1.5m/s
m2=45kg
V2=2.2m/s
so (60)(1.5)+(45)(2.2)=159 kgm/s
To find the Resultant velocity of the lover(s) - plural (signalling inelastic)
you would take the sum of the m1+m2, which is 105kg-> then create the equation 159/105, which is the total momentum divided by the total mass, which would equate to the resultant velocity of an inelastic collision.
Hope this helped.
A horizontal pipe of inner diameter 2.2 cm carries water with a density of 1000.0 kg/m3 flowing at a rate of 1.5 kg/s. If the pipe widens to 2.5 cm, what is the speed of the water in the wider part
The speed of the water in the wider part will be 1.194 m/sec. Speed is a time-based quantity. Its SI unit is m/sec.
What is speed?Speed is defined as the rate of change of the distance or the height attained.
The given data in the problem is;
The initial diameter is,[tex]\rm d_1 = 2.2 \ cm[/tex]
initial radius,
[tex]r_1 = \frac{d_1}{2} \\\\ r_1 = \frac{2.2}{2} \\\\ r_1 = 1.1\ cm[/tex]
The initial crossection area;
[tex]\rm A_1 = \pi r_1^2 \\\\ \rm A_1 = 3.14 \times (1.1\times 10^{-2})^2 \\\\ \rm A_1 =3.8 \times 10^{-4} \ m^2[/tex]
The final crossection area;
[tex]\rm A_2 = \pi r_2^2 \\\\ \rm A_2 = 3.14 \times ( 2 \times 10^{-2})^2 \\\\ \rm A_2 = 12.56 \ m^2[/tex]
The initial flow rate is;
R = density ×velocity ×area
[tex]\rm R = \rho A V \\\\ 1.5 = 1000 \times V_1 \times 3.8 \times 10^{-4} \\\\ V_1 = 3.947 \ m/sec[/tex]
The speed of the water in the wider part will be;
From the continuity equation;
[tex]\rm A_1 V_1 = A_2V_2 \\\\\ 3.8 \times 10^{-4} \times 3.947 = 12.56 \times 10^{-4} \times V_2 \\\\ V_2= 1.194 \ m/sec[/tex]
Hence, the speed of the water in the wider part will be 1.194 m/sec.
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Given that the Sun's effective temperature is 5700K with its radius of 696,340 km. How many hydrogens convert to helium in a second if all the energy of the sun is coming from the hydrogen to helium fusion process
The number of hydrogens converts to helium in a second will be 3. If all the energy of the sun is coming from the hydrogen to helium fusion process.
What is helium fusion process?When the temperature in the core hits around 100 million degrees, the helium will begin to fuse into carbon in a mechanism known as the triple-alpha process
The given data in the problem is;
The Sun's effective temperature is,T= 5700K
The radius IS,R=696,340 km.
The energy emitted is found is;
[tex]\rm E = 4 \pi \sigma R^2T^4 \\\\ \rm E = 4 \times 3.14 \times 5.67 \times 10^{-8} \times (6.9634 \times 10^8)^2 \times (5700)^4 \\\\ E= 36451449876.6 \times10^{16} \ Joule \\\\ E = 3.65 \times 10^{26} \ J[/tex]
If 26.7 MeV energy is required in hydrogen to helium fusion process;
[tex]\rm 26.7 \ MeV = 4 \ hydrogen \\\\ 26.7 \times 10^6 \times 1.6 \times 10^{19} = 4 \ hydroge n \\\\ 3.65 \times 10^{26} = \frac{4 \times 3.65 \times 10^{26} }{26.7 \times 1.6 \time 10^{-13}}[/tex]
[tex]\rm n = 0.34 \times 10^{39} \\\\ n= 3.4 \times 10^{38} \ hydrogen[/tex]
Hence, hydrogens convert to helium in a second will be 3.4 ×10³⁶.
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If f(x) = -x2+x-1 then value of f(f(2)) is
Answer:
-13
Explanation:
Function
f(x) = -x² + x - 1Solving
Substitute 2 in place of xf(2) = -(2)² + 2 - 1f(2) = -4 + 2 - 1f(2) = -3f(f(2)) = f(-3)f(-3) = -(-3)² - 3 - 1f(-3) = -9 - 3 - 1f(f(2)) = -13Which property will eventually be the same for two objects after thermal
energy is transferred between them?
O A. Internal energy
O B. Pressure
O C. Temperature
O D. Density
Answer: temperature
Explanation: i took the quizz
Can someone write how to determine the viscosity of glycerin by falling ball ?
Answer:-
The terminal velocity of a steel ball 2 mm in diameter falling through glycerin is 44×10 - ²
cm/s (Given that specific gravity of steel = 8, specific gravity of steel =8, specific gravity of glycerin a 1.3, viscosity of glycerine 8.3 poise.) .
Of the three sciences, physics, chemistry, and biology, the most complex is
A. physics because it involves many mathematical equations.
B. chemistry because there are so many possible combinations of atoms.
C. biology because it is based upon both the laws of chemistry and physics.
D. All three of these sciences are equally complex.
Answer:
I would probably say C to be completely honest
Explanation:
If you agree make sure to give me a like
Pls help first person to answer correct become brainliest
Answer:
See image below
Explanation:
See image
Which type of light is emitted from objects with the highest temperatures?.
The workdone In pulling a body which weighs 30N along a horizontal plane by a constant force of 20N is 320J. Find the distance moved
Answer: The answer is 800 J
Explanation:
A galaxy containing substantial amounts of dark matter will.
Answer:
spin faster
Explanation:
-
Answer:
A galaxy containing substantial amounts of dark matter will spin faster
(10 points)
a. Ball 3 has the lowest speed.
b. Ball 1 has the lowest speed.
c. All three balls have the same speed.
D. The speed of the balls depends on their mass.
Answer:
option b has the correct answer of given statement
Which of the following describes the structure of an airplane wing?
A. To help the airplane change directions
B. Smooth, wide shape with a curved edge
C. To lift the airplane off the ground
D. Flat, thin metal with silver stripes
Answer:
B.Smooth, wide shape with a curved edge
Suppose that the mirror is moved so that the tree is between the focus point F and the mirror. What happens to the image of the tree?
(1 point)
The image of the tree between the focus point F and the mirror moves behind the curved mirror. This is further explained below.
What is a mirror?A smooth surface such as glass that reflects pictures In the mirror, the law of reflection says that when a ray of light is produced to fall on a reflecting surface, the reflected ray has its angle of reflection, the incident ray has its angle of reflection, and the reflected ray is normal to the surface at a point of incidence.
In conclusion, Behind the curved mirror, the image shifts.
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Answer: The image moves behind the curved mirror.
Hope this helps :)
Which study led to the conclusion that atoms are not indivisible ?
Answer:
don't know
Explanation:
don't know cause i don't read physic
Answer:
Study of static electricity and the condition under which electricity is conducted by different substances.
Do you think the benefits outweigh the risks for using nuclear energy? If not, why not? If so, explain.
You are on a camping trip, far away from city lights. You look up into the dark night sky, and see lots of stars, some brighter, some dimmer. All the stars you see with your unaided eye are
All the stars you see with your unaided eye are part of the galaxy called the milky way.
What is a galaxy?The term galaxy refers to a collection of stars. We have to note that various planets have their own individual galaxies.
All the stars you see with your unaided eye are part of the galaxy called the milky way.
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20 points
Which of the following is true about the potential energy between charged particles. Choose the two that apply.
a
Potential energy increases as like charges get closer.
b
Potential energy increases as opposite charges get closer.
c
Potential energy remains the same between like charges as they move apart.
d
Potential energy increases as any charges move closer together.
e
Potential energy decreases as opposite charges get closer.
f
Potential energy decreases as like charges get closer together.
Answer:
(a) and (b)
Both will follow the rule
This is due to property of charges.
As in case of gravitational potential energy as it increases as height increases.
In case of electrical potential energy it will increase as charges comes close.
Explanation:
have a good day:))
Answer:
i beleive its A and B will both follow the rule
This is due to property of charges.
hope this helped
Explanation:
If your car tachometer says your engine is moving at 1200 RPM, then what is it's angular velocity in Rad/sec?
Answer:
125.66 R/s
Explanation:
First 1200 r / min = 20 r/sec
20 r/s * 2pi Radians / r = 40 pi Radians / sec = 125.66 R/s
An elevator carrying a person of mass m is moving upward and slowing down. How does the magnitude f of the force exerted on the person by the elevator floor compare with the magnitude mg of the gravitational force?.
The force f of the elevator on the man keeps reducing as the elevator keeps going up while the gravitational force mg keeps increasing moving upwards.
What is an elevator?An elevator is an electrical device that lifts people up and down a tall building or structure.
for the elevator to go up, f > mg.
for the elevator to come down mg > f.
Analysis
since the force on the man is f = ma
where a is the acceleration of the elevator, then it means when a increases, f will increase and when it decreases, f would decrease. slowing down means a, is decreasing going up and this reduces the force as the elevator keeps going up.
on the other hand, gravity acts faster on bodies that are slower in motion so since g, increases going up, mg would also increase.
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How can you increase the force required to move an object without changing the mass of the object?
To increase the force required to move an object without change mass is : To increase the acceleration of the object
Force acting on an object
Given that Force = Mass * acceleration
An increase in the acceleration of an object in motion will result in a proportional increase in the Force required to move the object becasue force of an object is directly proportional to the acceleration of an object.
Hence we can conclude that To increase the force required to move an object without change mass is To increase the acceleration of the object.
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What is the best prediction for what will happen when all of the hydrogen in the sun has undergone fusion? helium nuclei will split to form hydrogen, and the sun will no longer release energy. helium nuclei will split to form hydrogen, and the sun will continue to release energy. helium nuclei will fuse to create heavier elements, but the sun will no longer release energy. helium nuclei will fuse to create heavier elements, and the sun will continue to release energy.
Helium nuclei splitting to form hydrogen, and the Sun will no longer release energy will occur when all the hydrogen in the sun undergoes fusion.
What is Fusion?This occurs when two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles.
In a situation where all the hydrogen in the sun has undergone fusion, the helium nuclei will split to form hydrogen, and the Sun will no longer release energy.
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The two pulses reflect off the boundaries of the string, and at some later time, they pass through the middle of the string and interfere. Below are six different sequences of snapshots taken as the two pulses meet in the middle of the string. Time increases from top to bottom in each sequence. Which sequence correctly represents the displacement of the string as the pulses interfere?.
Option C is the sequence which correctly represents the displacement of the string as the pulses interfere.
What is Interference?This is defined as a phenomenon that occurs when two waves meet while traveling along the same medium.
When a wave pulse encounters a free end then it reflects the same way as incident path which is depicted in option C.
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a 1200 kg car travels at 20 m/s. what is the momentum
Answer:
24000
Explanation:
Calculate the buoyant force of air (density 1.20 kg/m3 ) on a spherical party balloon that has a radius of 17.0 cm .
The buoyant force of air will be 246.25 N.Buoyancy force is the multiplication of the density, gravity, and volume.
What is buoyancy force?A fluid exerts an upward force against the weight of a partly or completely submerged item. The weight of the overlying fluid causes pressure to rise with depth in a column of fluid.
The buoyancy force is found by the formula as;
[tex]\rm F_B = \rho g V[/tex]
[tex]\rm \rho[/tex] is the density
g is the acceleration due to gravity
V is the volume
[tex]\rm F_B[/tex] is the buoyancy force
The volume of the spherical balloon is;]
[tex]\rm V= \frac{4}{3} \pi r^3 \\\\ \rm V= \frac{4}{3} \times 3.14 (17.0 \times 10^{-2})^3 \\\\ V=0.2056 \ m^3[/tex]
The buoyancy force is found by the formula as;
[tex]\rm F_B = \rho g V \\\\ \rm F_B = 1.20 \times 9.81 \times 0.2056 \\\\F_B = 246.25 \ N[/tex]
Hence the buoyant force of air will be 246.25 N.
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The ________________ is the body’s system of turning food into energy.
A.
metabolism
B.
digestive system
C.
stomach
D.
endocrine system
Answer:
B
Explanation:
Digestive as it has enzymes that turn food into energy.
A dentist uses a concave mirror to examine a tooth that is 1cm in front of the mirror. The image of the tooth forms 10cm behind the mirror.
a. What is the mirror's radius of curvature?
b. What is the magnification of the image?
a) The mirror's radius of curvature will be 2.7 cm
B) The magnification of the image will be 4.0.
What is a concave mirror?When a hollow spherical is divided into pieces and the exterior surface of each cut portion is painted, it forms a mirror, with the inner surface reflecting the light.
From the mirror equation;
[tex]\frac{1}{p}+\frac{1}{q} =\frac{1}{f} \\\\ \frac{1}{1}+\frac{1}{-10} =\frac{1}{f} \\\\ \frac{1}{f} = 1-\frac{1}{10} \\\\ \frac{1}{f} = \frac{9}{10} \\\\ f= 1.1111[/tex]
Hence,
The radius of curvature is twice of the focal length;
[tex]\rm R = 2f \\\\ \rm R = 2\times 1.111 \\\\ R=2.2222 \ cm[/tex]
Hence, the mirror's radius of curvature will be 2.7 cm.
The magnification factor is found as;
[tex]\rm m = \frac{-q}{p} \\\\ m = \frac{-(-10)}{1} \\\\ m = 10[/tex]
Hence, the magnification of the image will be 4.0.
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what is the electric potential energy of a charge that experiences a force of 4.6 x 10-5N when it is 5.8 x 10-5 m from the source of the electrical field
Answer:
what is this i am in class 7 i dont know and not read yet
A car travels 120 km in the first 2 hours and 100 km in the next 2 hours.
What is the car’s average speed?
240 km/h
440 km/h
55 km/h
128 km/h
A grating has 350 rulings/mm. What is the longest wavelength for which there is a 6.0th-order diffraction line
For a grating having 350 rulings/mm, longest wavelength is mathematically given as
lambda_max=3.704*10^{-7}m
What is the longest wavelength for which there is a 6.0th-order diffraction line?Generally, the equation for the wavelength is mathematically given as
lambda=dsin\theta/6
Therefore, for lamda_max theta=\pi/2
lambda_max=dsin\pi/2 /6
In conclusion
lambda_max=d/6
lambda_max=3.704*10^{-7}m
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