A driver of a car traveling at 15.0 m/s applies the brakes, causing a uniform acceleration of -2.0 m/s squared. How long does it take the car to accelerate to a final speed of 10.0 m/s? How far has the car moved during the braking period?
Answer:
a) 2.5secs
b) 31.25m
Explanation:
a) From the question, we are given;
Initial speed u = 15m/s
Final speed v = 10.0m/s
Acceleration =-2.0m/s²
Required
How long it takes take the car to accelerate (Time t)
Using the equation of motion
v = u+ at
10 = 15+(-2)t
10 = 15-2t
10-15 = -2t
-5 = -2t
t = 5/2
t = 2.5secs
Hence it takes the car 2.5secs to accelerates.
b) We are to find distance S
Using the equation
S = ut + 1/2at²
S = 15(2.5)+1/2(-2)(2.5)²
S = 37.5-6.25
S = 31.25m
Hence the car as moved by 31.25m during the breaking period.
Hiii I think the answer might be 3.3 seconds,not exaclty sure tho
I need help with all of these questions
Answer:
This was my best estimation of the answers
Each tyre of a car has an area of 100 cm2 in contact with the ground. The car has a mass of 1600 kg. The weight of the car is equally distributed amongst the four tyres.The gravitational field strength g is 10 N / kg.What is the pressure exerted on the ground ?
A. 4.0 N/cm2
B. 16 N/cm2
C. 40 N/cm2
D. 160 N/cm2
The pressure exerted on the ground is 40 N/cm². Hence, option (C) is correct.
What is pressure?It is the ratio between the force being applied and the surface area being applied to. The force delivered perpendicularly to an object's surface per unit area across which that force is dispersed is known as pressure.
SI unit of pressure is Pascal or Newton/meter².
Given parameters:
Mass of the car: m = 1600 kg.
Gravitational field strength: g = 10 N/kg
Area of each tyre of car: a = 100 cm²
Hence, total force applied by the car = mg = 1600 × 10 Newton = 16000 Newton.
As the weight of the car is equally distributed amongst the four tyres; force applied on each tyre = 16000 Newton/4 = 4000 Newton.
Hence, the pressure exerted on the ground = force/area
= 4000/100 N/cm²
= 40 N/cm²
hence, option (C) is correct.
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A particle with mass of 200 kg is acted on by a net force of 4.5N. The acceleration of the particle is most nearly
Find the distance Sara walks from A to B, B to C
then C to D?
Answer:
16m
Explanation:
5m pluse 5m equals 10m 3m pluse 3m equals 6m 10m pluse 6m equals 16m thats ju ansar
Which organisms release carbon dioxide as waste?
Which of the following is related to a person’s self-concept?
A) what neighborhood he or she lives in
B) his or her sense of self-worth
C) how good an athlete he or she is
D) how attractive he or she is
Answer:
Im not a 100 percent sure but i thinks it za A
Explanation:
3. What is the best way to help with
mining problem in the future?
Answer:
1) Mining companies have an impressive track record for delivering continuous improvements in safety and risk governance standards. We have no doubt that the professionalism and expertise present within the industry will ensure that any new and emerging risk challenges are dealt with in an equally determined fashion.
2) Insurers have recognized the approach and achievements of mining companies in identifying, mitigating and retaining their risks. Many mining companies have close and longstanding relationships with their insurers built through regular dialogue with mining company executives and visits to mining sites and processing facilities.
3) This document should be of value to any organization involved in this ever-evolving industry.
4) The very nature of mining natural resources means that many businesses will have operations in some of the most remote and inhospitable areas in the world and very often coupled with a high susceptibility to natural catastrophe.
5) In addition to the traditional risk factors, the mining industry now faces an even wider range of challenges. Factors such as climate change, new technologies, economic uncertainties and secure supply of key consumables like electricity, water, gas and other fuels are all difficult to predict and bring additional complications to securing appropriate balance sheet protection.
A child kicks a ball horizontally with a speed of 4.8 m/s off a deck 3.5 m off the ground. How far, in meters, from the deck does the ball land on the ground?
Answer:
2.605m
Explanation:
Using the formula for calculating Range (distance travelled in horizontal direction)
Range R = U√2H/g
U is the speed = 4.8m/s
H is the maximum height = ?
g is the acc due to gravity = 9.8m/s²
R = 3.5m
Substitute into the formula and get H
3.5 = 4.8√2H/9.8
3.5/4.8 = √2H/9.8
0.7292 = √2H/9.8
square both sides
0.7292² = 2H/9.8
2H = 0.7292² * 9.8
2H = 5.21
H = 5.21/2
H = 2.605m
Hence the height of the ball from the ground is 2.605m
PLEASE HELP!
Formulate a conclusion about what happens to the pH of a substance when an
acid and base are mixed.
Answer:
They gon' hate me regardless, that's why I do what I do (what I do)
See me in person i'm flawless (I'm flawless girl), i might just snatch up your dude (hahahaha)
Explanation:
i just want to be....appreciated
Do machines create less work? Example: pulley system
Answer:
Technically, no the work of building machines is hard but in the long run, Yes they are easier after they're built.
Explanation:
Describe the differences between the change in momentum when a car is stopped with the brakes and when a car is stopped in a collision.
Explanation:
When a car is breaking, the brakes apply pressure/force onto the wheels(car) which allows it to slow down.
When the car collides with an object, it is exerting a force upon that object to which it applies an equal and opposite force on the car.
I think this is what you are asking for.
Hope This Helps :)
Does natural selection produce a change in individuals or populations?
Explanation:
Natural selection is the process through which populations of living organisms adapt and change. Individuals in a population are naturally variable, meaning that they are all different in some ways. This variation means that some individuals have traits better suited to the environment than others
A 1500 kg car is accelerated by a force of 2000 N for 15 s.
What is the acceleration of the car?
If the car started at rest, how fast is the car going after 15s? (1pts)
How far (∆x) would the car have traveled after the 15s? (1pts)
By Newton's second law, the car has acceleration a such that
2000 N = (1500 kg) a
a = (2000 N) / (1500 kg)
a = 4/3 m/s² ≈ 1.33 m/s²
After 15 s, the car will attain a speed of
(4/3 m/s²) (15 s) = 20 m/s
It will have traveled a distance ∆x such that
(20 m/s)² - 0² = 2 (4/3 m/s²) ∆x
∆x = (20 m/s)² / (8/3 m/s²)
∆x = 150 m
I need help with this one
Coulombs law
100 points and brainliest
Answer:
my dad is a physics professor so when he comes home i will tell him to answer the question for you
When convection occurs in the atmosphere:
A.
Warm air sinks and cool air rises.
B.
Warm air rises and cool air sinks.
C.
Warm air and cool air sinks.
D.
Warm air and cool air rises. MARK BRAINLEST HELP!
Answer:
The answer is B.
Explanation:
As the Earth's surface warms from the sun, for instance, the air above it warms and rises. If the circumstances permit, this air may continue to climb while cooling and generating cumulus clouds. Thus, option B is correct.
What role of convection in atmosphere?Convection currents are created in the troposphere by surface heating. Convection currents are produced as the Earth's surface warms from the Sun's rays and the air near it rises as a result of heat absorption.
The effect of differential heating is convection currents. Warm, lighter (less dense), and rising matter rises while cool, heavier (more dense), falling matter falls. Convection currents are the circulation patterns that are produced by this movement in the Earth's atmosphere, oceans, and mantle.
Therefore, The air cools, gets denser, and sinks back toward the surface as it ascends in the troposphere.
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HELP PLZZZ!!!! Hurry
3. What does doubling the number of coils do to the strength of the electromagnet?
4. What does doubling the voltage do to the strength of the electromagnet?
5. Using the graph, predict how many paper clips a 7.5 V battery would pick up for both the 25-
coil electromagnet and the 50-coil electromagnet.
6. Calculate the slope of the 25-coilline and the 50-coil line to determine the average number of
paper clips that a 1 V battery would pick up.
Answer:
3. When the number of turns, N is doubled, the strength of the electromagnet is also doubled
4. Doubling the voltage, doubles the strength of the electromagnet
5. The number of paper clips a 7.5 V battery would pick is approximately 28 paper clips
The number of paper clips a 7.5 V battery would pick is 59 paperclips
6. For the 50-coil electromagnet, the average number of paper clips a 1 V battery would pick is approximately 7 paperclips
For the 50-coil electromagnet, the average number of paper clips a 1 V battery would pick is 16 paperclips
Explanation:
3. The Magnetomotive Force, MMF = The Number of Turns on the Coil, N × The Current I Flowing in the Coil, I
∴ MMF = N × I
When the number of turns, N is doubled, the magnetomotive force, MMF is also doubled, and the strength of the electromagnet is doubled
4. Given that the voltage, V applied to the coil = The current, I flowing × The resistance, R of the coil, we have
V = I × R
Therefore, for a given constant resistance in the coil, doubling the voltage, doubles the current and therefore doubles the strength of the electromagnet
5. The average slope for the 25-coil electromagnet = (23 - 12)/(6 - 3) = 3.[tex]\bar 6[/tex]
The number of paper clips a 7.5 V battery would pick = 12 + (7.5 - 3) × 11/3 = 28.5 paperclips ≈ 28 paper clips
The average slope for the 50-coil electromagnet = (48 - 26)/(6 - 3) = 7.[tex]\bar 3[/tex]
The number of paper clips a 7.5 V battery would pick = 26 + (7.5 - 3) × 22/3 = 59 paperclips
6. The slope calculated from a start point of approximately 0.4 V, is given as follows;
The slope for the 25-coil electromagnet = (12 - 6)/(3 - 0.4) = 30/13
Therefore, for the 25-coil electromagnet, the average number of paper clips a 1 V battery would pick = 6 + (1 - 0.4) × 30/13) = 96/13 ≈ 7 paperclips
The slope for the 50-coil electromagnet = (26 - 13)/(3 - 0.4) = 5
Therefore, for the 50-coil electromagnet, the average number of paper clips a 1 V battery would pick = 13 + (1 - 0.4) × 5 = 16 paperclips
3. When the number of revolutions, N, is twice, the electromagnet's strength is doubled as well.
4. Doubling the voltage doubles the electromagnet's strength.
5. The number of paper clips selected by a 7.5 V battery is 59.
6. For a 50-coil electromagnet, a 1 V battery would pull up around 7 paperclips on average. The average number of paper clips picked by a 1 V battery for a 50-coil electromagnet is 16 paperclips.
What is electromagnet?The magnetic field of an electromagnet is created by an electric current. Electromagnets are caused from conducting wire wriggled into a coil.
A magnetic field is created in the hole by a current passing through the wire.
The magnetic field production is increased by;
1) increasing the number of turns
2) increase the area of the loop
3) by moving the magnet faster
Answer for the following given options as follows;
3. When the number of revolutions, N, is twice, the electromagnet's strength is doubled as well. Because the no of coils in the circuit is directly proportional to the strength of electromagnet.
4. From the ohm's law principal doubling the voltage twice the current and hence the electromagnet's strength for a given constant resistance in the coil increases.
5. For the 25-coil electromagnet, the average slope is ;
[tex]\rm m_{avg}= \frac{23-12}{6-3} \\\\ m_{avg}= 3[/tex]
The number of paper clips selected by a 7.5 V battery is;
[tex]\rm n = 12+ (7.5-+3)\times \frac{11}{3}\\\\n = 28.5[/tex]
For the 50-coil electromagnet, the average slope;
[tex]\rm (m_{avg})_{50}= \frac{48-26}{6-3} \\\\\ \rm (m_{avg})_{50}= 7[/tex]
The number of paper clips selected by a 7.5 V battery is;
[tex]\rm N = 26+(7.5-3) \times \frac{22}{3} \\\\ N= 59[/tex]
The following is the slope determined from a starting position of around 0.4 V:
For the 25-coil electromagnet, the slope is;
[tex]\rm m_{25}=\frac{12-6}{3-0.4} \\\\\ m_{25}=\frac{6}{2.6} \\\\ m_{25}=\frac{30}{13}[/tex]
As a result, the average number of paper clips a 1 V battery would choose for the 25-coil electromagnet is;
[tex]\rm N_{25}=6+ (1-0.4)\times \frac{30}{13} \\\\ N_{25}=\frac{96}{13} \\\\ N_{25}= 7 \ paperclip[/tex]
For the 50-coil electromagnet, the slope is;
(26 - 13)/(3 - 0.4) = 5.
As a result, the average number of paper clips picked by a 1 V battery is;
[tex]\rm N'_{50}= 13+ (1-0.14)\times 5 \\\\ N'_{50}=16[/tex]
Hence,the average number of paper clips picked by a 1 V battery for a 50-coil electromagnet is 16 paperclips.
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A boy is exerting a force of 70 N at a 50-degree angle on a lawnmower. He is accelerating at 1.8 m/s2. Round the answers to the nearest whole number.
What is the mass of the lawnmower?
What is the normal force exerted on the lawnmower?
The lawnmower accelerates in the positive horizontal direction, so that the net horizontal force is, by Newton's second law,
(70 N) cos(-50°) = m (1.8 m/s²)
where m is the mass of the lawnmower. Solve for m :
m = ((70 N) cos(-50°)) / (1.8 m/s²)
m ≈ 25 kg
The lawnmower presumably doesn't get lifted off the ground, so that the net vertical force is 0. If n is the magnitude of the normal force, then by Newton's second law,
n - m g + (70 N) sin(-50°) = 0
n = m g + (70 N) sin(50°)
n = (25 kg) (9.8 m/s²) + (70 N) sin(50°)
n ≈ 300 N
Cobalt (Co) has an atomic mass of 59 and an atomic number of 27. Which statement correctly describes an atom of cobalt?
O A. An atom of cobalt contains more neutrons than protons.
B. An atom of cobalt contains more electrons than protons.
O C. An atom of cobalt contains the same number of neutrons and protons.
O D. An atom of cobalt contains the same number of neutrons, electrons and protons.
Answer:
Option A. An atom of cobalt contains more neutrons than protons.
Explanation:
From the question given above, the following data were obtained:
Mass number = 59
Atomic number = 27
Next, we shall determine the number of protons in the atom. This is illustrated below:
Atomic number of an element is simply defined as the number of protons in the atom of the element. Thus,
Atomic number = proton number
Atomic number = 27
Therefore,
Proton number = 27
Next, we shall determine the neutron number. This can be obtained as follow:
Mass number = 59
Proton number = 27
Neutron number =?
Mass number = Proton + Neutron
59 = 27 + Neutron
Collect like terms
Neutron = 59 – 27
Neutron number = 32
Next, we shall determine the number of electrons. This can be obtained as follow:
Since the atom is neutral i.e it has no charge, then, the number of protons and electrons are equal. Thus,
Electron number = Proton number
Proton number = 27
Therefore,
Electron number = 27
Summary:
Mass number = 59
Atomic number = 27
Proton number = 27
Neutron number = 32
Electron number = 27
From the above, we can see that the atom of cobalt contains:
1. More neutrons than protons.
2. The same number of protons and electrons.
Therefore, option A gives the correct answer to the question.
State Newton's three laws of motion in your own words and give an example for each one that helps to explain it in everyday life.
Answer:
The first law is an object won’t change its place unless a force hits it
The second law is the force on an object equivalent to the mass times its acceleration
The third law is when two object meet, they both apply forces on each other making them go in opposite directions
Explanation:
The chimney of an oil lamp cracks when touched with rhe brade of cold knife?why
Answer:
The extreme difference between the hot chimney and the cold knife makes the chimney expand and contract so quickly it cracks.
Explanation:
Hope this helped!
Answer:
When a blade of cold knife is touched to hot glass chimney there is a sudden drop of temperature on the spot where the blade touches. As a result it cracks.
Explanation:
When a blade of cold knife is touched to hot glass chimney there is a sudden drop of temperature on the spot where the blade touches. This decrease in temperature makes the glass to contract. The stress developed on the site of contraction is responsible for the cracking of the glass chimney.
A spring has a spring constant of 120 N/m. How much energy is stored in the spring as it is stretched a distance of 0.20 meter?
Answer:
2.4J
Explanation:
Given parameters:
Spring constant = 120N/m
Extension = 0.2m
Unknown:
Amount of energy = ?
Solution:
The energy stored in this stretched spring is called the elastic potential energy.
It can be derived using the expression below:
Elastic Potential energy = [tex]\frac{1}{2}[/tex] ke²
k is the elastic constant
e is the extension
Insert the parameters;
Elastic potential energy = [tex]\frac{1}{2}[/tex] x 120 x 0.2² = 2.4J
A 90 kg body is taken to a planet where the acceleration due to
gravity is 2.5 times that of the earth. What is the weight of this body
on the surface of this planet? Take g = 10 m/s?.
Answer:
225 kg.
Explanation:
Since the gravity is 2.5 times than that of the Earth, g on that planet = (10 * 2.5) m/s = 25 m/s.
Hence, the weight of the body would be (90 * 2.5) kg, aka 225 kg.
Hope this helped!
What are some examples of X-Ray waves
Answer:
X - Rays
Explanation:
Hope it Helps!
:)
Answer: Black holes, sun, stars, neutron stars
Explanation:
deducing the acceleration = deduce the gradient of velocity-time graphs
true or false?
Answer:
True
Explanation:
Understanding the relationship between change in velocity with time will explain to you how the object is accelerating or decelerating. This means acceleration is a ratio calculated from the change in velocity of an object and change in time. In a velocity time graph, the y-axis represents the velocity and the x-axis represents the time.
The slope of the graph m = Δ y-axis values/Δ x-axis values
m= Δvelocity / Δ time
m= Δ v / Δ t ------this the definition of acceleration so;
a= Δ v / Δ t
Conclusion : The slope/gradient of a velocity -time graph is acceleration.
Where does compression often occur?
Answer:
a convergent boundary^^
Explanation:
hope it helped
What is the work energy transfer equation?
Answer:
The equation used to calculate the work done is: work done = force × distance. W = F × d. This is when: work done (W) is measured in joules (J)
Answer:
The equation used to calculate the work done is: work done = force × distance. W = F × d. This is when: work done (W) is measured in joules (J)
Explanation:
The net work done on a particle equals the change in the particle's kinetic energy:
A projectile is fired at an angle such that the vertical component of its velocity
and the horizontal component of its velocity are BOTH equal to 30 m/s.
a. Using the approximate value of g = +/-10 m/s2, how long in time does it take for the
ball to reach its high point?
Answer:
It takes 3 seconds to reach its high point
Explanation:
Projectile Motion
In a projectile motion (or 2D motion), the object is launched with an initial angle θ and an initial velocity vo.
The components of the velocity are
[tex]v_{ox}=v_o\cos\theta[/tex]
[tex]v_{oy}=v_o\sin\theta[/tex]
The speed in the horizontal direction at any time t is:
[tex]v_y=v_o\sin\theta-g.t[/tex]
The time taken to reach the maximum height is when vy=0, or:
[tex]\displaystyle t_m=\frac{v_o\sin\theta}{g}[/tex]
We are given the y-component of the velocity, thus:
[tex]\displaystyle t_m=\frac{30~m/s}{10~m/s^2}[/tex]
[tex]t_m=3~s[/tex]
It takes 3 seconds to reach its high point
Which of the following would be an example of mechanical energy?
Elastic Energy, Kinetic Energy, Gravitational Potential Energy
Gravitational Potential Energy, Thermal Energy
Electric Potential Energy, Nuclear Energy, Kinetic Energy
Magnetic Energy, Elastic Potential Energy
Answer:
B
Explanation:
Answer:
b
Explanation:
Kylie has a mass of 54 kg and is jogging at a velocity of 3 m/s what is Kylie’s kinetic energy?