juie ran eight laps around her school's quarter mile track in 18 minutes. her average velocity was _______m/s
Answer:
About 3m/s
Explanation:
If Julie ran eight quarter mile laps, then she ran a total of 1/4 * 8=2 miles. 2 miles is about 3220 meters, and 18 minutes is 1080 seconds, meaning that her average velocity was about 3m/s. Hope this helps!
Please can someone help me.
I need answer ASAP. will mark Brainliest.
Starting from rest on a level road a girl can reach a speed of 5m/s in 10s on her bicycle. Find
a) the acceleration,
b) the average speed during the 10s,
c) the distance she travels in 10s.
Explanation:
acceleration=∆v/∆t
∆v=5-0
∆t=10-0
a=5/10
a= 0.5m/s²
speed= distance/time
average speed =5+0/2
=5/2
=2.5m/s
speed=distance/time
5=d/10
d=10*5
=50m
An electric current always produces a magnetic field that is ______ to the field. A. perpendicular B. parallel C. at a 37° angle D. none of the above
Answer:perpendicular
Explanation:
The electric current always generated the magnetic field that should be perpendicular to the field.
Relationship of electric current and magnetic field:In the case when the work should be compassed when the pointing is to be done along with the magnetic field lines so this represent that there should be the magnetic field that should be near the wire via the current should be flowing. here the magnetic field generated by the electric current should always be perpendicular to the current flow direction.
Learn more about electric current here: https://brainly.com/question/24301101
Which phrase best describes the time period in which the current body of scientific knowledge was developed? A. Just over the last 50 years B. Throughout all of history C. Mostly in the 20th century D. Mostly during Roman times
Answer:
The correct option is;
B. Throughout all of history
Explanation:
A body of knowledge comprises of a given collection of concepts, activities and terms that represents a professional discipline that is outlined by the associated scholarly society, therefore, scientific knowledge, being comprised of very diverse field of knowledge, with different approaches and changing understanding is taking as a process of learning about the universe data collection, experimenting analysis and communication with a theme of systems, equilibrium, models and constant change which makes the basis of the body of scientific knowledge to be throughout all of history.
A car moving at a rate of 72 km per hr. How does it moves if it stop after 4 seconds?
Answer:
80 meters
Explanation:
Answer:
So the distance covered is 80meters
Explanation:
Speed=72km/h=20m/s
Time=4seconds
Distance covered=?
As we know that
Speed=distance covered/time taken
Speed*time taken=distance covered
Putting values
Distance covered=20m/s*4s
Distance covered =80meters
I hope it will help you
Which of the following are valid expressions?
Answers:
validnot validvalidnot validnot validvalidIn short, the boxes you check will be box 1, box 3, box 6.
================================================
Explanation:
It's not stated, but I'm assuming that A,B,C are three dimensional vectors
I'll go through each answer choice to say whether it's valid or not.
---------------------------
Choice 1
A x B is some vector
(A x B) x C is some other vector. Cross products produce vectors as outputs, when the two inputs are both 3D vectors. The output vector is the same dimension as the inputs.
Overall, the expression (A x B) x C is valid.
---------------------------
Choice 2
A dot B is a scalar
(A dot B)C is some vector
A dot (B x C) is a scalar
We cannot add a scalar to a vector. The given expression (A dot B)C + A dot (B x C) is not valid
---------------------------
Choice 3
B x C is a vector
B dot (B x C) is scalar
A[ B dot (B x C) ] is a vector in the form kA with k as a scalar.
The overall expression is valid
---------------------------
Choice 4
B x C is a vector
B(B x C) is not valid. We need to use a dot or cross symbol between the B and (B x C).
If we had kB with k as a scalar, then we don't need a symbol between them.
---------------------------
Choice 5
A dot B is a scalar
Scalars are not allowed when it comes to cross products, so (A dot B) crossed with anything is not valid.
---------------------------
Choice 6
B x C is some vector
A dot (B x C) results in a scalar
The expression is valid
Part B
What were the reactants of the first experiment in the video?
1
х,
Font Sizes
A -
A
: EEE
Answer:
zinc and hydrochloric acid
Explanation:
Answer:
The reactants he used in the first experiment were zinc metal and hydrochloric acid.
Explanation:
edmentum
Which is the process by which a gas changes to a solid? deposition evaporation freezing sublimation
Answer:
Deposition
Explanation:
Answer:
deposition
Explanation:
qasdsfa32
ASAP WILL GIVE BRAINLIEST Take a piece of paper, some nails and a magnet bar, place a magnet at the centre of the paper, and sprinkle the nails. Observe what will happen to the nails and what other phenomena you can observe.
Answer: find the answer in the explanation
Explanation:
When a magnet is placed at the centre of the paper, and the nails are sprinkled on the paper, what will happen to the nails is that, the nails will form a pattern on the paper according to the magnetic field of the bar magnetic pole.
Other phenomena you can observe are:
1.) The nails will align themselves and show some lines of forces which is equivalent to the magnetic field lines
2.) The direction of the line of forces
3.) The strength of the magnetic field pole.
1) Which one of the following is vector,
B) Momentum
C) Mass
A) Energy
D) Temperature
Answer:
momentum is a vector quantity that points in the same direction as velocity
Explanation:
The tip of second's hand of a clock take 60 seconds to to move once on the circular dial of the clock. If the radius of the dial of the clock be 10.5 cm, calculate the speed of the tip of the second's hand of the clock.
Answer:
( About ) 1.1 cm / s
Explanation:
We know that the time it takes the clock's second hand to move is 60 seconds. Respectively the radius of this clock is given to be 10.5 centimeters.
_______________________________________________________
Let us apply the formula speed = distance traveled / time. Here the " distance traveled " is the circumference of the clock, or 2πr - where we can pose π as 3.14. In other words, Speed = 2πr / time. Substitute known values to solve for the Speed,
S = 2 * 3.14 * 10.5 / 60,
Speed = ( About ) 1.1 cm / s
Hope that helps!
11. What is the wavelength of an earthquake wave if it has a speed of 5000 m/s and a frequency of 10 HZ
step#1
step#2
step#3
Answer:
500 m
Explanation:
The applicable relation is ...
wavelength = speed/frequency
wavelength = (5000 m/s)/(10 cycles/s) = 500 m/cycle
The wavelength is 500 meters.
Animal studies indicate that
Answer: mammals may be relatively better at solving problems than birds.
Answer: A
Explanation:
mammals may be relatively better at solving problems than birds
Para que ángulo el alcance es igual a la altura máxima en un lanzamiento de proyectil ideal sobre un plano horizontal. Translation: For which angle the range equals the maximum height in an ideal projectile launch on a horizontal plane. a) 45º b) 60º c) 76º d) 90º
Answer:
76°Explanation:
In projectile,
Maximum height = [tex]\frac{u^{2}sin^{2} \theta }{2g}[/tex] and range = [tex]\frac{u^{2}sin2\theta }{g}[/tex]
u = velocity of the body
[tex]\theta[/tex] = angle of launch
g = acceleration due to gravity
If the range equals the maximum height in an ideal projectile launch on a horizontal plane, this means;
[tex]\frac{u^{2}sin^{2} \theta }{2g} = \frac{u^{2}sin2\theta }{g}[/tex]
since [tex]sin2\theta = 2sin\theta cos\theta[/tex]
[tex]\frac{u^{2}sin^{2} \theta }{2g} = \frac{u^{2}2sin\theta cos\theta }{g}\\\frac{sin\theta}{2} =2cos\theta \\sin\theta = 4cos\theta\\\frac{sin\theta}{cos\theta} = 4\\tan\theta = 4\\\theta = tan^{-1} \\4\theta = 75.9^{0}[/tex]
The angle at which the range equals the maximum height in an ideal projectile launch on a horizontal plane is approximately 76°
A person, with a mass of 50.0 kg, stands on a weighing scale in a lift which is moving
upwards with a uniform acceleration of 5.0 m/s
2
. What would be the reading on the
scale?
(A) 490 N (B) 250 N (C) 740 N (D) 240 N
Answer:
D
Explanation:
Because I just had that answer
I NEED HELP PLEASE, THANKS! :) A rubber rod can be charged negatively when it is rubbed with wool. What happens to the charge of the wool?
Answer:
A rubber rod can be charged negatively when it is rubbed with wool. If the rubber rod is charged negatively, a positive charge is induced into the wool. Remember, whenever two neutral objects are rub against each other , an opposite charge is induced in both of the objects.
The impact on the charge of the wool should be explained below:
Impact on the wood charge:A rubber rod could be charged negatively at the time when it is rubbed with wool. In the case when the rubber rod is charged negatively, a positive charge should be induced into the wool. Also, whenever two neutral objects are rubbed against each other, an opposite charge should be induced in both of the objects.
Learn more about charge here: https://brainly.com/question/13030344
I NEED HELP PLEASE, THANKS! :)
Radio waves can bend around buildings. An X-ray technician stands behind a wall during the use of her machine. What does this tell you about the relative wavelengths of these two types of invisible light?
Answer:
Radio waves have a wavelength between [tex]10^{-9}m[/tex] and [tex]10^{-12}m[/tex]
While,
X rays have a wavelength between 1m and 10km.
=> It is one of the condition of diffraction that the obstacle (coming in the way) must be comparable with the size of the wavelength.
=> This shows, that radio waves have a wavelength which is comparable with the size of buildings and can really easily diffract through it
=> While, X-rays are big enough to diffract through the wall.
So, if an X-ray technician stands behind a wall during the use of her machine, she will remain safe.
A boat travels at 15 m/s in a direction 45° east of north for an hour. The boat then turns and travels at 18 m/s in a direction 5° north of east for an hour.
What is the magnitude of the boat’s resultant velocity? Round your answer to the nearest whole number.
Answer:
16 m/s
Explanation:
First, find the displacement in the east direction.
x = (15 m/s sin 45°) (3600 s) + (18 m/s cos 5°) (3600 s)
x = 102,737 m
Next, find the displacement in the north direction.
y = (15 m/s cos 45°) (3600 s) + (18 m/s sin 5°) (3600 s)
y = 43,831 m
Find the magnitude of the displacement.
d = √(x² + y²)
d = √((102,737 m)² + (43,831 m)²)
d = 111,697 m
Finally, find the resultant velocity.
v = d / t
v = (111,697 m) / (7200 s)
v = 15.5 m/s
Rounded to the nearest whole number, the resultant velocity is 16 m/s.
The total distance from a house to a school to is 9.5 km. A student travels all the way from his house to the school and back to his house again. The displacement during this journey is:
9.5 km
19 km
0
explain your answer
Answer:
0
Explanation:
Displacement is a vector from initial to final point. Because initial and final point are the same, so displacement is 0.
Which is a resource that the National Park Service manages?
Answer:
Natural areas, historical areas, and recreation areas
Answer:
the answer is B wildlife refuges
Explanation:
Explain briefly the first aid measure that should be taken incase of poisoning
Answer:
How you treat someone who may have been poisoned depends on:
The person's symptoms
The person's age
Whether you know the type and amount of the substance that caused poisoning
If you are concerned about possible poisoning, call Poison Help at 800-222-1222 in the United States or your regional poison control center. Poison control centers are excellent resources for poisoning information and, in many situations, may advise that in-home observation is all that's needed.
An electron moving along the +x-axis enters a magnetic field. If the electron experiences a magnetic deflection in the -y direction, what is the direction of the magnetic field in this region?
Answer:
Into the page (negative z-axis)
Explanation:
We have a charge moving towards the left (as it is an electron we reverse the direction.)
We have an output motion downwards.
We know that the magnetic field would be in [tex]90^o[/tex] to both direction of charge and motion.
Using Fleming's Left Hand Rule.
Thumb for direction of thrust. (Downwards)
Field for direction of magnetic field (unknown)
Middle finger for direction of current (To the left)
We can determine that the magnetic field would be going into the negative z axis.
a car travels 30 miles in two hours, what is its speed?
Answer:
15 mph
Explanation:
t ÷ d
time ÷ distance
30÷2
=15
Answer:
15 mph
Explanation:
Speed can be found using the following formula.
s=d/t
where d is the distance and t is the time.
The car traveled 30 miles in 2 hours. Therefore, the distance is 30 miles and the time is 2 hours.
d=30 miles
t=2 hours
s= 30 miles/2 hours
Divide 30 by 2
s=15 miles/hour
The car's speed is 15 miles per hour.
I NEED HELP PLEASE, THANKS! :)
Tom’s father is 48 years old. He is not able to see nearby objects clearly.
-What may be the reason for his vision problem?
-Where are images formed in this type of defected vision?
-How is this defect corrected?
Answer:
Explanation:
1) Hypermetropia (better known as Farsighted- this is why nearby objects seem blurry for him)
2) In such instances, image are typically formed farther from the near point
3) Such defects are quite common so there are common procedures such as using convex lens which can restore the sight to normal.
Look at figure D . Explain what will happen if a larger mass it put on the force meter
it will experience great force
What is the power of 10 when 157,821 is written in scientific notation
Answer: 5
We write the number 157,821 by moving the decimal place to the left
until the first number, taking note of the number of times you moved it.
Therefore, it is written as 1.57821 x 10^5. The power of 10 would be 5.
Which of the following best describes atoms with low electronegativity?
A. They tend to lose electrons and become cations.
B. They tend to lose electrons and become anions.
C. They tend to gain electrons and become cations
D. They tend to gain electrons and become anions.
when light passess from air into glass the angle of incidence is always _______ the angle of refraction
Explanation:
The angle of incidence is always smaller than the angle of refraction
A student has a 3v cell and the resistance in the circuit totals 6 ohms. How much current would flow in a series circuit?
Answer:
[tex]I=0.5 \:A[/tex] is the correct answer.
Explanation:
Using the ohm's law, we have:
[tex]V=IR\\\\I=\frac{V}{R}=\frac{3}{6}\\\\I=0.5 \:A[/tex]
Best Regards!
Archer shoots his arrow towards a target at a distance of 90 m and hits bullseye . Calculate the acceleration and time taken by the arrow to hit the target with a velocity of 90.0 m/s
Answer:
acceleration = 45 m/s²
Time = 20 seconds
Explanation:
We are given;
Distance; s = 90m
Final velocity;v = 90 m/s
Since shot from rest, initial velocity;u = 0 m/s
So, to find the acceleration, we can use Newton's 2nd law of motion which is;
v² = u² + 2as
Where a is acceleration
Plugging in the values;
90² = 0² + 2a(90)
8100 = 180a
a = 8100/180
a = 45 m/s²
Now, for the time, we will use Newton's 1st law of motion which is;
v = u + at
Where t is time;
So;
90 = 0 + 4.5t
90 = 4.5t
t = 90/4.5
t = 20 seconds