Answer: 4 s
Explanation:
Given
The applied force is 70 N
mass of the rock is 28 kg
initial velocity [tex]u=25\ m/s[/tex]
final velocity [tex]v=15\ m/s[/tex]
Deceleration provided by force is
[tex]a=-\dfrac{70}{28}=-2.5\ m/s^2[/tex]
using the equation of motion
[tex]v=u+at\\\Rightarrow 15=25-2.5t\\\Rightarrow 2.5t=10\\\Rightarrow t=4\ s[/tex]
Which is an example of a polyatomic ion?
Answer:
Well-known examples of such polyatomic ions are the sulfate ion (SO42–), the hydroxide ion (OH–), the hydronium ion (H3O+), and the ammonium ion (NH4+).
Explanation:
Answer:
is there more context to go with this question? Like a photo?
I will give it my best shot anyhoo
Explanation:
Polyatomic ions: they are covalently bonded groups of atoms and having a positive or negative charge caused by the formation of an ionic bond with another ion.
And if your question is anything like the one I had a few days ago on a test, your answer would be something like "Both hydroxide cation (OH -) and phostphate cation (PO 4 3 -) are polyatomic ions)
How can a conductor be made superconductor?
Answer:
a superconductor in a magnetic field and you'll make electric currents flow through its surface. These currents create a magnetic field that exactly cancels the original field trying to get inside the superconductor and repelling the magnetic field outside.
Explanation:
What kind of waves can cause the most damage on the earth's surface?
Answer:
Surface waves, in contrast to body waves can only move along the surface. They arrive after the main P and S waves and are confined to the outer layers of the Earth. They cause the most surface destruction. Earthquake surface waves are divided into two different categories: Love and Rayleigh.
Explanation:
Hope this helped Mark BRAINLIEST!!!
Answer:
Surface waves are the seismic waves that cause the most damage.
Explanation:
Which statement is false?
A) Doubling the mass halves the acceleration
B) Doubling the force doubles to acceleration
C) Doubling the mass doubles the acceleration
Statement C is false. Doubling the mass doubles the acceleration is the wrong statement.
What is force?Force is defined as the push or pulls applied to the body. Sometimes it is used to change the shape, size, and direction of the body.
Force is defined as the product of mass and acceleration. Its unit is Newton.
Mathematically, the force is;
[tex]\rm F= ma[/tex]
If force is constant, the mass is inversely proportional to the acceleration. If the mass is double in that condition, acceleration is halved.
Doubling the mass doubles the acceleration is the wrong statement.
Hence, statement C is false
To learn more about the force, refer to the link;
https://brainly.com/question/26115859
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A baseball is struck home plate and acquires a speed of 60m/s. It rises to a height of 100.0 m above its starting level. Find its speed at the height
Answer:
40 m/s.
Explanation:
From the question given above, the following data were obtained:
Initial velocity (u) = 60 m/s
Height (h) = 100 m
Acceleration due to gravity (g) = 10 m/s²
Final velocity (v) =?
The velocity at height 100 m can be obtained as follow:
v² = u² – 2gh (since the ball is going against gravity)
v² = 60² – (2 × 10 × 100)
v² = 3600 – 2000
v² = 1600
Take the square root of both side
v = √1600
v = 40 m/s
Thus, velocity at height 100 m is 40 m/s
What device increases voltage?
A. generator
B. motor
C. step-down transformer
D. step-up transformer
Your answer would be C.
A step-up transformer is a transformer that raises voltage from main to secondary by having more secondary winding turns than primary winding turns.
Hope this helps; have a great day!
An electron (e = 1.6 x 10-19 C) is traveling at 4.00 x 107 m/s due North in a horizontal plane through a point where the earth’s magnetic field has a component to the North of 2.00 x 10-5 T and a downward (in to the earth) of 5.00 x 10-5 T. Calculate the magnetic force (magnitude and direction) on the electron and its acceleration. Me = 9.11 x 10-31 kg
Answer:
Explanation:
Force on the electron due to magnetic field 's north component will be zero because both velocity of electron and direction of magnetic field are same .
Force due to downward component of magnetic field
= B q v where B is magnetic field , q is charge moving and v is velocity of charge
F = 5 .00 x 10⁻⁵ x 1.6 x 10⁻¹⁹ x 4 x 10⁷
= 32 x 10⁻¹⁷ N
acceleration = F / m where m is mass of electron
= 32 x 10⁻¹⁷ / 9.11 x 10⁻³¹
= 3.5 x 10¹⁴ m/s²
A 2,000 kg freight train is traveling on the railroad tracks from Birmingham to Mobile. It traveling at a speed of 25 m/sec. What is the kinetic energy of this train?
Answer:
The correct answer is "625,000 J".
Explanation:
The given values are:
Mass,
m = 2,000 kg
Speed,
v = 25 m/sec
As we know,
⇒ [tex]Kinetic \ energy=\frac{1}{2} (mass \times speed^2)[/tex]
Or,
⇒ [tex]K.E=\frac{1}{2}(mv^2)[/tex]
On substituting the values, we get
⇒ [tex]=\frac{1}{2}(2,000\times 25^2)[/tex]
⇒ [tex]=1000\times 625[/tex]
⇒ [tex]=625,000 \ J[/tex]
A baseball sits motionless near first base on a baseball diamond. What statement best explains why the baseball remains motionless?
Answer:
Because no one is using that ball, so it is motionless
Answer:
No one is using the ball (dead ball) and therefore it is motionless and out of play
Explanation:
Joe is standing on the pedal of a bicycle. If his mass of 65 kg, the pedal makes an angle of 55º above the horizontal, and the pedal is 18 cm from the center of the chain ring, how much torque does he exert?
a. 4 N·m c. 94 N·m b. 18 N·m d. 122 N·m
...
Answer:
94 N-m
Explanation:
Joe is standing on the pedal of a bicycle. If his mass of 65 kg, the pedal makes an angle of 55º above the horizontal, and the pedal is 18 cm from the center of the chain ring. The amount of torque Joe exert is 94 N-m.
What is torque?The force that can cause an object to rotate along an axis is measured as torque. Similar to how force accelerates an item in linear kinematics, torque accelerates an object in an angular direction. A vector quantity is a torque.
Torque is defined as Γ = r×F = r.F.sin(θ). In other words, torque is the cross product of the force vector, where 'θ' is the angle between r and F, and the distance vector (the distance between the pivot point and the place where force is applied).
Given in question mass 65 Kg so force, F = mg = 637 N
Distance r = .18 m and θ = 55 so sinθ = .82
Torque = rFsin(θ) putting the values, we get
Torque = 94 N-m.
The amount of torque Joe exert is 94 N-m.
To learn more about torque refer to the link:
brainly.com/question/6855614
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You serve a volleyball with a mass of 2.5 kg. The ball leaves your hand with a speed of 23 m/s. What is the kinetic energy of the ball?
Answer:
661.25, I believe!
Explanation:
KE = (1/2)(2.5)(23)^2
KE=(1.25)(529)
KE= 661.25
list down the different phases of the Moon
Answer:
new Moon.
waxing crescent Moon.
first quarter Moon.
waxing gibbous Moon.
full Moon.
waning gibbous Moon.
last quarter Moon.
waning crescent Moon.
Explanation:
Answer:
NEW MOON
WAXING CRESCENT
FIRST QUARTER
WAXING GIBBOUS
FULL MOON
THIRD QUARTER
WANING GIBBOUS
WANING CRESCENT
Explanation:
HOPE IT HELPS
Which of the following best describes why tidal energy is considered a renewable energy resource? A. The Moon receives energy from the Sun, which is a renewable resource. B. Humans can create more tidal energy by setting up more tidal energy plants. C. Ocean water will never be exhausted. D. Tidal energy is replaced naturally by the Moon's gravity.
Answer:
D. Tidal energy is replaced naturally by the Moon's gravity.
Explanation:
The reason tidal energy is considered a renewable energy resource is that Tidal energy is replaced naturally by the Moon's gravity. The Moon's gravity creates bulges on the side of Earth that is closest and farthest from the Moon. These bulges also pull water causing high tides in those areas. As the Earth rotates these areas experience low tide while the areas that had low tide now experience high tide. This constant shift creates tidal energy every day, which is replenished naturally.
16. A strong acid has a pH close to 7
A.True
B.False
Answer:
I think it's true.
Hope this helps .
Explanation:
The pH scale measures how acidic or basic a substance is. The pH scale ranges from 0 to 14. A pH of 7 is neutral. A pH less than 7 is acidic.
Suppose, the same angular momentum is transferred to two rotating bodies of different moment of inertia , how will you compare the angular velocities of the two bodies as a result of angular momentum transfer.
Answer:
As per the law of conservation of angular momentum, the angular velocity will be higher for the body with a lower moment of inertia and vice versa.
Explanation:
Angular momentum L of a body is given by:
[tex]L=I\times \omega[/tex]
Now when the same angular momentum is transferred to two different bodies with different moment of inertia, the body with a higher moment of inertia will have lower angular velocity and vice versa.
2. The force between charges is 7 N. The distance between the charges is 4 x 10-6 m. If one of the charges is 2 x 10-8 C, what is the strength of the other charge?
3. A pair of equal charges are separated by .75 m. There's a 2500 N force acting on them. What is the strength of the charge?
Plz help!!!!!!
Answer:
2) 6.22 × 10^-13
3) 4.56 × 10^-4
Explanation:
What is the average speed of inchworm 1 at 2 minutes?
I made the chart as clear as I could.
Answer: 2
Explanation:
The average speed of the inchworm 1 at 2 minutes in the given graph is determined as 0.025 m/s.
What is average speed?The average speed of an object is the rate of change of displacement of the object with time.
The average speed of the inchworm 1 at 2 minutes is calculated as follows;
v = D/t
v = 3 m/(2 min x 60 s)
v = 0.025 m/s
Thus, the average speed of the inchworm 1 at 2 minutes is 0.025 m/s.
Learn more about average speed here: https://brainly.com/question/6504879
Which applications, either for diagnostic purposes or for therapeutic purposes, involve the use of X-rays? Check all that apply.
CT scan
MRI
radiography
brachytherapy
laser eye surgery
radioisotope imaging
external beam radiation therapy
fluoroscopy
Answer:
1,3,7,8
Explanation:
Edge 2021
A rod is given a charge of +16.7 UC, how many extra protons does It contain?
Answer:
We know that the electronic charge is 1.6 E-19 coulombs
Therefore 1 coulomb of charge contains 1.6 E19 electrons
A charge of 16.7 E6 coulombs therefore contains
N = 16.7 E6 * 1.6 * E-19 = 2.67 E-12 electrons
Also, the charge on the proton equals that on the electron
Given the height of rod,length of shadow of tree and length of shadow of the rod, estimate the height of the tree? Given:height of rod=150cm,Length of shadow of the rod=120cm and length of shadow of the tree =800cm
Answer:
1000 cm.
Explanation:
To obtain the estimated tree height :
(Height of rod / length of rod shadow) = (height of tree / length of tree shadow)
Substituting values into the formula :
(150cm / 120 cm) = (height of tree / 800 cm)
Using cross multiplication :
Height of tree * 120 = 150 * 800
Height of tree = (150 * 800) / 120
Height of tree = 120,000 / 120
Height of tree = 1000
Hence, estimate height of tree = 1000 cm
What is the polarity of each of the earths magnetic poles ? Explain you answer
Answer:
When you put un-like poles together (South facing North) you can feel magnetic attraction. In the Northern Hemisphere, your compass needle points North, but if you think about it for a moment, you will discover that the magnetic pole in the Earth's Northern Hemisphere has to be a South polarity.
Help!!! Please need it fast. If correct I’ll give b
Answer:
if bother parents have brown eyes but they carry the allele for blue eyes a quarter of the kids will have blue eyes and three quarters will have brown eyes. hope this help I'm sorry if it doesn't.
A rock with a mass of 6 grams has greater thermal energy than a rock with a mass of 7 grams. True or false?
Answer:
Explanation:
False
What current flows through a 15 ohm fixed resistor when it operates on a 120-volt outlet?
Answer: current is 8.0 A
Explanation: R= U/I I = U/R = 120 V/15 Ω= 8.0 A
What is another term for a pull on an object? O A. Acceleration O B. Speed O c. Force O D. Velocity
Answer:
Acceleration
Explanation:
in an exothermic reaction, chemical energy is converted to ____ energy.
FILL IN THE BLANK.
MECHANICAL OR THERMAL.
Answer:thermal energy
Explanation:
please mark this answer as brainliest
A 1.2 m long wave travels 11.2 m to a wall and back again in 4.0 s. What is
the FREQUENCY of the wave*
Answer:
f = 4.67 Hz
Explanation:
We can approximate the wave as a traveling wave, therefore the speed of the wave is constant
v = d / t
the total distance remember, in going to the wall and back is
d = 2 11.2 = 22.4 me
we substitute
v = 22.4 / 4.0
v = 5.6 m / s
now we can use the relationship between the speed of the wave, its wavelength and u frequency
v =λ f
f = v /λ
f = 5.6 / 1.2
f = 4.67 Hz
How much work does the electric field do in moving a -7.7 hC charge from the ground to a point whose potential is +55 V higher?
Define the types of friction and give FOUR examples of each
Static Friction
Rolling Friction
Sliding Friction
Fluid Friction
Answer:
Static Friction - acts on objects when they are resting on a surface
Sliding Friction - friction that acts on objects when they are sliding over a surface
Rolling Friction - friction that acts on objects when they are rolling over a surface
Fluid Friction - friction that acts on objects that are moving through a fluid
Explanation:
Examples of static include papers on a tabletop, towel hanging on a rack, bookmark in a book , car parked on a hill.
Example of sliding include sledding, pushing an object across a surface, rubbing one's hands together, a car sliding on ice.
Examples of rolling include truck tires, ball bearings, bike wheels, and car tires.
Examples of fluid include water pushing against a swimmer's body as they move through it , the movement of your coffee as you stir it with a spoon, sucking water through a straw, submarine moving through water.
It is a good idea to read or exchange text messages during all of the following times EXCEPT:
A.
while driving a car
B.
while eating lunch
C.
while waiting at the doctor's office
D.
while riding a bus
Please select the best answer from the choices provided.
A
B
C
D
Answer: A while driving a car. It is unsafe
Answer:
It is a good idea to read or exchange text messages during all of the following times except while driving a car.
Explanation:
Eating lunch and using your phone is very safe. The only way I can see it being bad is if you handed your phone to some toddlers and took it back without wiping it off!
If you're waiting for your appointment or waiting to reach your destination, then there is also no harm. As long as you are not driving the bus or you're not the doctor working on patients while texting, then this should be alright.
This leaves us with driving. The commercials tell us. Common knowledge tells us. Hopefully, parents or colleagues or even your own kids (I've had to do this to my dad countless times before) have told you this...
DO NOT TEXT WHILE DRIVING.
So many accidents happen solely for this reason. People, just put down the phone and wait 'til you're at a red light or, even better, when you reach your destination.
So no, it is not a good idea to read OR exchange text messages while driving. Any other time? Well, go ahead! But if you're in that driver seat and your currently in the road with other cars, take into consideration the fact you are not the only person there. Keep everyone safe and drop that phone!
....
My bad, I got long winded. Hope this helped!
Source(s): TV Commercials, myself.