An engineer in a locomotive sees a car stuck on the track at a railroad crossing in front of the train. When the engineer first sees the car, the locomotive is 260 m from the crossing and its speed is 26 m/s. If the engineer's reaction time is 0.51 s, what should be the magnitude of the minimum deceleration to avoid an accident? Answer in units of m/s 2
Answer:
The right answer is "1.369 m/s²".
Explanation:
The given values are:
Distance (s)
= 260 m
Initial speed (u)
= 26 m/s
Reaction time (t')
= 0.51 s
During reaction time, the distance travelled by locomotive will be:
⇒ [tex]s'=ut'[/tex]
[tex]=26\times 0.51[/tex]
[tex]=13.26 \ m[/tex]
Remained distance between locomotive and car:
⇒ [tex]x=s-s'[/tex]
[tex]=260-13.26[/tex]
[tex]=246.74 \ m[/tex]
Now,
The final velocity to avoid collection is, V = 0 m/s
From third equation of motion:
⇒ [tex]V^2=u^2+2ax[/tex]
On putting the estimated values, we get
⇒ [tex]0=(26)^2+2\times a\times 246.74[/tex]
⇒ [tex]0=676+493.48a[/tex]
⇒ [tex]493.48a=-676[/tex]
⇒ [tex]a=-\frac{676}{493.48}[/tex]
⇒ [tex]a=1.369 \ m/s^2[/tex]
The table shows the mass of and acceleration due to gravity for several
planets in the solar system. If air resistance is ignored, on which planet would
a space probe with a mass of 250 kg have the highest speed after falling 25
m?
Planet
Mass, 1024 kg
Acceleration due to gravity
Venus
4.87
8.9
Earth
5.97
9.8
Uranus
86.8
8.7
Saturn
568
9
A Earth
B. Saturn
C. Uranus
D. Venus
C. Uranus
What is acceleration due to gravity?Acceleration due to gravity is the acceleration gained by an object due to gravitational force.
Its SI unit is m/s2. It has both magnitude and direction.
According to the question,
Planet would a space probe with a mass of 250Kg
Distance is 25m.
As
Mass does not affect the speed of falling objects, As there is only gravity acting on it.
The mass of Uranus is:
m=8.681×10²⁵kg
The radius of Uranus is: r = 2.556 \times
Hence , Uranus is the answer
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Answer: Uranus 8.7
Explanation:
Because mass does not effect the velocity of a falling object, only gravity effects it and time. The equation is change in Velocity= 9.8m/s^2 times t (for time). So, ignore the mass and choose the lowest acceleration in the chart if your question asks you for the lowest speed.
plzz help it for my civics class which answer is it?????????????
Answer:
Bill of rights is the correct answer
Someone had broken into Sam's house! Police came to investigate and a crime scene analyst collected evidence: broken glass, a piece of torn cloth, swabs from blood drops. Sam watched the crime scene analyst and thought he'd like to do that one day. It was a scientific way to solve puzzles! "You'd better get busy and study!" said his mother. "You know forensic scientists must have strong backgrounds in __________."
A) chemistry.
B) geology.
C) law.
D) mathematics.
A shopper in a supermarket takes a box of sugar from a shelf that is 1.5 m high because he is going to bake some muffins. He also needs to get some blueberries. The sugar has a weight of 5N. What Potential Energy did the sugar have before it was taken from the shelf?
Answer:
7.5 Joules.
Explanation:
Potential energy can be defined as an energy possessed by an object or body due to its position.
Mathematically, potential energy is given by the formula;
[tex] P.E = mgh[/tex]
Where, P.E represents potential energy measured in Joules.
m represents the mass of an object.
g represents acceleration due to gravity measured in meters per seconds square.
h represents the height measured in meters.
Given the following data;
Weight of sugar = 5N
Height = 1.5m
[tex] P.E = mgh[/tex]
But we know that weight = mg = 5N
Substituting into the equation, we have;
[tex] P.E = 5 * 1.5 [/tex]
[tex] P.E = 7.5 J[/tex]
Therefore, the potential energy the sugar had before it was taken from the shelf is 7.5 Joules.
The potential energy of the sugar at the given position before it was taken from shelf is 7.5 J.
The given parameters;
height of the shelf, h = 1.5 mweight of the sugar, W = 5 NThe potential energy of the sugar at the given position before it was taken from shelf is calculated as follows;
P.E = mgh
P.E = Wh
P.E = 5 x 1.5
P.E = 7.5 J
Thus, the potential energy of the sugar at the given position before it was taken from shelf is 7.5 J.
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What is the density of a 150cm 3 block with a mass of 700 grams?
Answer:
The Density of the block is 4.667g/mL
Explanation:
Given the following data;
Mass of block = 700g
Volume of block = 150cm³
Density = ?
Density can be defined as mass all over the volume of an object.
Simply stated, density is mass per unit volume of an object.
Mathematically, density is given by the equation;
[tex]Density = \frac{mass}{volume}[/tex]
Substituting into the equation, we have;
[tex]Density = \frac{700}{150}[/tex]
Density = 4.667g/mL
Main Street is approximately 0.25 miles long, How many yards long is Main Street if I mile is
equal to 1760 yards?
Answer:
440
Explanation:
1 mile =1760 yards
0.25 miles =?
[tex] \frac{0.25 \times 1760}{1} [/tex]
=440 yards
what is good givernance
Answer:
measuring
Explanation:
In international development, good governance is a way of measuring how public institutions conduct public affairs and manage public resources in a preferred way. Governance is "the process of decision-making and the process by which decisions are implemented"
Explanation:
way of measuring how public institutions conduct public affairs and manage public resources in a preferred way.
A scientific law seeks to explain why an event ocurred
True or false
I thank it’s true hope u have a good day
Which of following best defines muscles?
A. long flexible tendons that connect bones
B. tough strong tissues that provide energy to perform physical activities
C. thick fibrous cartilage that act when sent electrical signals
D. smooth long fibers that are controlled by the skeletal system
It's that time of month!!!
Answer:
B
Explanation:
Trust me
The best explanation of the muscles from the given list of statements would be tough strong tissues that provide energy to perform physical activities, therefore the correct answer is option B .
What is exercise?Exercise is an activity that includes the physical movements of the body and results in fitness, wellness , and healthiness of the person to protect and lower the risks of getting diseases. It allows the person to maintain a healthy weight .
As given in the problem statement we have to find out the best explanation for the muscles from the given list of statements ,
The greatest explanation for muscles from the selection of phrases provided would be that they are tough , powerful tissues that provide us the energy to engage in physical activity , hence choice B is the correct response .
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1. Express the following quantities in scientific notation.
a. 5800 m
c. 302 000 000 m
b. 450 000 m d. 86 000 000 000 m
Answer:
a. 5.8 ³
C. 3.02⁸
D. 4.5⁵
B.8.6¹⁰
Explanation:
Why do clouds, and sometimes precipitation, typically form along a frontal boundry such as a warm front?
Answer:
In the case of a warm front, the warm, less dense air rises up and over the colder air ahead of the front. Again, the air cools as it rises and its moisture condenses to produce clouds and precipitation.
Explanation:
Hope this helps u
Crown me as brainliest:)
A person starts at the origin and then walks 6 m to the west, and then 8 m south.
a. How far from the origin is the student’s final position?
b. What was the direction with respect to the origin?
please mark brainliest
Explanation:
Let the east direction to be i^ and north direction be j^.
Thus displacement of the man S=8i^+6j^
So, magnitude of displacement ∣S∣=62+82=100=10 m
Contact and Non-contact Forces Assignment
Now that you have learned about forces, complete and submit the following assignment.
For the following situations, describe the contact and non-contact forces that are involved.
Situation
Contact Force(s)
Non-Contact Force(s)
A book sitting on a shelf
A soccer player kicking a ball; the ball soaring through the air and landing on the ground
A hiker in the woods reading her compass to determine which direction to go
A child on a sled; first, the child is sitting at the top of the hill, waiting his turn; then, the child pushes off and slides down the hill, eventually coming to a stop.
Answer:
I didn't know the subject but I researched and understood so...here goes!!
A book resting on a shelf: contact force- reaction force
non contact force: gravitational force
Soccer ball- contact force- air resistance
non contact force- gravitational force
Compass- contact force- reaction force
non contact force- magnetic force
child on sled- contact force- friction
non contact force- gravitational force
Explanation:
HURRY PLEASE!!
A car's horn emits a constant frequency as it accelerates away from a
stationary listener. Which of the following quantities appears to change for
the listener?
A. frequency only
B. frequency and pitch
C. pitch and loudness
D. amplitude and loudness
Answer:
answer is C
Explanation:
just did this
Answer:
Pitch and loudness
C.
Explanation:
what is the iv and the DV in a rocket
an independent variable (IV) that you can change. • Typical IV's might be number of fins, length of rocket, type of material, mass of the rocket. • Choose one dependent variable (DV) and make three launches per DV for each IV for a total of. six launches..
Explanation:
Oven mitts reduce which type of thermal energy transfer when you take a hot
pan out of an oven?
A. Conduction
B. Translation
C. Convection
D. Radiation
Answer:
A) Conduction
Explanation:
The mitt keeps the heat from reaching your hand through conduction
Answer: A.conduction
Explanation: i got it right on my test!
Kim sees a dog jump onto the road. Her response time before she hits the brakes is 0.3 seconds. How far will her car travel during her response time if she is moving at 20 m/s?
Answer:
6 seconds i think
Explanation:
Some students in a Chemistry lab conducted an investigation in which they added four different solid substances to separate beakers of water. They stirred the mixtures for one minute and then recorded their observations in the table below.
Which most likely caused a new substance to be formed when mixed with water?
A. Substance 1
B. Substance 2
C. Substance 3
D. Substance 4
A car accelerates from rest to 37.3 m/s
in 7 sec. What is the acceleration?
Answer:
poopgshshsh
Explanation:
cacawusususu
I need help with this physics question
1. A boat initially moving at 10 m/s accelerates at 2 m/s2 for 10 s. What is the velocity of the boat after 10 seconds?
Answer:
5 m/s is the answer so yeah
How long will it take for a rock to fall 12 meters?
Answer:
1.56 seconds.
The rock will take 1.56 seconds to fall.
We have a rock.
We have to determine how long it will take for a rock to fall 12 meters.
State the second equation of motion.The second equation of motion is -
S = ut + 1/2 at²
According to the question -
initial velocity = u = 0 m/s
acceleration = a = 9.8 m/s²
distance = S = 12 meters
Using the second equation of motion -
S = ut + 1/2 at²
12 = 0 + 0.5 x 9.8 x t²
12 = 4.9t²
t² = 2.45
t = 1.56 seconds
Hence, the rock will take 1.56 seconds to fall.
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True or false. The center of gravity and center of mass of an object need to be in the same spot.
Answer: this is true
Answer:
it is actually false, the center of gravity is; the unique point where the weighted relative position of the distributed mass sums to zero, thus the center of mass doesn't have to be in the same spot as the center of gravity
Explanation:
Also i took the test and got it right.
An independent variable is ______________________and is plotted on the ______ axis
A dependent variable is ________________________ and is plotted on the ______ axis.
Answer:
The independent variable is plotted on the abscissa (also called the x-axis or horizontal axis), while the dependent variable is plotted on the ordinate (also called the y-axis or vertical axis). The dependent variable is the one whose value changes as a result of changes in the independent variable.
Explanation:
2. How have human activities and natural processes influenced the gradual or sudden change in global temperature? (You need a minimum of 5 complete sentences.)
Answer:
Human activities and natural processes have influenced the change in the global temperature by the following processes
1) Green house gas such as carbon dioxide, methane, ozone, nitrous oxide and fluorinated gases produced by the combustion of fossil fuels the use of industrial chemicals, the production of coal, and natural gas
2) Deforestation which reduces the natural process of conversion of carbon dioxide to oxygen, thereby, increasing the greenhouse gases in the atmosphere
3) The accumulation of the greenhouse gases in the atmosphere results in the trapping of heat in the atmosphere, causing the atmospheric temperature to rise
4) Changes in the amount of energy produced by the Sun can result in an increase or decrease in the atmospheric temperature
5) Volcanic activity that occurs at a sufficiently large scale can produce sulfur dioxide that blocks the rays of the Sun from reaching the Earth, resulting in a change of atmospheric temperature.
Explanation:
Answer:
Green house gas such as carbon dioxide, methane, ozone, nitrous oxide and fluorinated gases produced by the combustion of fossil fuels the use of industrial chemicals, the production of coal, and natural gas
Explanation:
2. Montesquieu's view of the separation of powers was later expressed in the United States Government through which document? A. The Declaration of Independence b. The United States Constitution c. The Two Treatises of Government d. The Social Contract
Answer: b. The United States Constitution
Explanation:
Montesquieu argued that the best form of government, was one where the legislative arm, executive arm, and judicial powers were separate. and in doing so helped kept each other in check to prevent any branch from becoming too powerful. Montesquieu’s separation of powers was not accurate when compared the government of England, But this was later adopted by Americans as the foundation of the U.S. Constitution.
Which statement best compares potential and kinetic energy?
A. Objects always have more potential energy than kinetic energy.
B. Only kinetic energy increases when the velocity of an object increases.
C. Only potential energy decreases when an object's height increases.
D. Objects always have more kinetic energy than potential energy.
Answer:
D
Explanation:
Because kinetic energy do have more than potential energy: kinetic energy is when a object is moving. Potential energy is when something is at rest and has no movement what so ever
Answer:
B. only kinetic energy increases when the velocity of an object increases.
Explanation:
got it right on the quiz, hope this helps!! :)
looking at the velocity vs time graph, between points b and c on the graph, the object was
1. at rest
2. decelerating
3.accelerating
4. going a constant velocity
If there is no electric current in a coil of wire with a permanent magnet at its
center, which statement must be true?
A. The wire is not moving relative to the magnet.
B. The coil of wire is shorter than the magnet.
C. The coil of wire is longer than the magnet.
D. The wire is moving relative to the magnet.
D. With respect to the magnet, the wire is in motion.
What'd happen if a magnet was inserted and removed from a copper wire coil?An electrical discharge is created when a wire loop as well as a bar magnetic are moved in tandem.This current is generated as a result of a change in the field's intensity near the coil.Both the system is a process and the induced emf that creates it are induced phenomena.
What is required to create an electric current in a magnet enclosed in a loop of wire?The electrons inside the wire are pushed when a magnet is moved around it or when a coil of wire is moved around a magnet, producing an electrical current.
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