Answer:
t = 9.14 s
Explanation:
We first analyze the accelerating motion by applying first equation of motion:
Vf₁ = Vi₁ + a₁t₁
where,
Vf₁ = Final Speed of Car before turning off engine
Vi₁ = Initial Speed of Car = 0 m/s
a₁ = acceleration of car = 25 m/s²
t₁ = time taken in accelerating motion
Therefore,
Vf₁ = 25t₁ ---------- equation (1)
Now, we apply second equation of motion:
s₁ = Vi₁ t₁ + (1/2)a₁t₁²
where,
s₁ = distance covered during accelerating motion
Therefore,
s₁ = (0)t₁ + (1/2)(25)t₁²
s₁ = 12.5 t₁² ----------- equation (2)
Now, we analyze the decelerating motion by applying first equation of motion:
Vf₂ = Vi₂ + a₂t₂
where,
Vf₂ = Final Speed of Car = 0 m/s
Vi₂ = Initial Speed of Car after turning off engine
a₂ = deceleration of car = - 3 m/s²
t₂ = time taken in decelerating motion
Therefore,
Vi₂ = 3t₂ ---------- equation (3)
Now, we apply second equation of motion:
s₂ = Vi₂ t₂ + (1/2)a₂t₂²
where,
s₂ = distance covered during decelerating motion
Therefore,
s₂ = (Vi₂)t₂ + (1/2)(-3)t₂²
s₂ = Vi₂ t₂ - 1.5 t₂²
using equation (3):
s₂ = 3 t₂² - 1.5 t₂²
s₂ = 1.5 t₂² ------------ equation (4)
Now, we know that the Final Velocity of accelerating motion (Vf₁) is equal to the initial velocity of decelerating motion (Vi₂):
Vf₁ = Vi₂
using equation (1) and equation (3):
25 t₁ = 3 t₂
t₁ = 0.12 t₂ ------------ equation (5)
Also, we know that sum of the distances is 200 m:
s₁ + s₂ = 200
using equation (2) and equation (4):
12.5 t₁² + 1.5 t₂² = 200
using equation (5):
12.5 (0.12 t₂²) + 1.5 t₂² = 200
3 t₂² = 200
t₂² = 200/3
t₂ = 8.16 s
substitute this in equation (5):
t₁ = 0.12(8.16 s)
t₁ = 0.97 s
Hence, the minimum time required for this motion is:
t = t₁ + t₂ = 0.97 s + 8.16 s
t = 9.14 s
2. (1) A piece of rubber is 50 cm long when a weight of
35 N hangs from it and is 85 cm long when a weight
of 70 N hangs from it. What is the spring constant
of this piece of rubber?
Answer
By F = -kx {-ve just indicating the sign of the force}
=>35 = k x (85-50) x 10^-2
=>k = 100 N/m
Again by F = -kx
what does it mean to say energy is conserved
Which of the following for an object should be known to calculate its density? (5 points)
A.the heat present in it
B.The amount of matter in it
C.The force of gravity acting on it
D.The space between the object and another object
is -3 a solution to equation 3x -5 = 4+ 2x
Answer:
No!
Explanation:
The correct answer is x = 9.
what is meant by absolute zero temperature?
Answer:
Absolute zero, temperature at which a thermodynamic system has the lowest energy. It corresponds to −273.15 °C on the Celsius temperature scale and to −459.67 °F on the Fahrenheit temperature scale.
What distance does a biker travel if he rides at a constant speed or 22 m/s for 45 seconds?
Answer:
it would be 990 m.
Explanation:
22 m/s x 45 seconds.
ANSWER QUICK PLS
1. What is the distance between a 900 kg compact car and a 1600 kg pickup truck if the gravitational force between them is about 0.0001 N?
Answer:
what was the answer? Was it 0.98?
Answer:
it's 98
Explanation:
The water cycle was described in the Scriptures long before modern scientists understood it.
True False
Answer:
False
Explanation:
Low humidity is typically associated with cold temperatures since cold air holds less water compared to warm air. While it is possible for indoor humidity to be as low as 10%, most people generally find humidity levels of about 40 to 45 percent comfortable.
Which statement describes how this diagram could be changed so that it
shows an electromagnet?
so
Battery
Ammeter
A. Place a second battery between the ammeter and the wire coil.
B. Add a magnetic metal core inside the coil of wire.
C. Add magnetic field lines around the wire coil,
D. Move the ammeter to the other side of the wire coil.
Answer:
b. add a magnetic metal core
Explanation:
a p e x test
Answer:
B. Add a magnetic metal core inside the coil of wire.
Explanation:
How are electrons involved in the formation of a bond between atoms?
Answer:
5
Explanation:
electrons can be more than det
When 560,000 is written in scientific notation, what is the power of 10?
Answer: 5
Explanation: In scientific notation you must bring one number to left of the decimal point. Therefore it is 5.6 × 10^5. Therefore the power of 10 is 5.
Calculate the gravitational potential energy of a 2 kg banana hanging 5
meters above the ground.
(Use 10 m/s2 for gravity)
Answer:
100 J
Explanation:
The potential energy is given by the formula ...
PE = mgh
= (2 kg)(10 m/s^2)(5 m) = 100 J
Which of these best describes why your weight would be different on another celestial body?
A. Different celestial bodies have different gravitational pulls
B. The smaller the celestial body, the greater weight
C. The farther the celestial body from the sun, the more the gravitational pull
D. Weight is constant, so it would not change
Answer:
A
Explanation:
The answer is A due to the gravity is stronger the greater the mass but the less the mass is the weaker the gravity. In conclusion, the answer is A because the strength of gravity depends on the mass.
6. Which formula could you use according to the scenario? Five grams of substance occupy 3 cm3 of a flask. Om = du OD Ot= d
Om = du OD Ot= d?
Explanation:
While studying bacterial cells, scientists measure the lengths of the cells in one colony. The chart shows their data. The scientists notice that one measurement stands out. How should the scientists best deal with this measurement? accept it as true and use 85 micrometers in the data when they find the average length accept it as true but say that it is the only cell that has ever been that long consider that there was an error during measuring and collect further data consider that it is possible but very unlikely for these bacterial cells to be so long
Answer:
Following are the solution to the given question:
Explanation:
Its best approach to this measurement ought to be to indicate that there was a mistake throughout the calculation, as well as the gathering of further details while researching cells for bacteria, directly measuring the cell length of a colony. This chart illustrates its data, which scientists have observed that there's still a measurement.
1.
Which is not a characteristic of a compound?
•has different properties from its component elements
•can be represented by a chernical formula
•different samples have different properties
•a pure substance made of two or more elements
Answer:
different sample have different properties is not a characteristics of a compound ,
Explanation:
because compound will always same properties no matter how quantity is
In addition to a reference point you also need distance and __________ to describe location
displacement
btw in not sure
which one?? please someone quick!
Answer:
i think its second law of motion.
Explanation:
Answer:
it’s the second law
Explanation:
What is a material that can dissolve in another material called?
Slippery
Physical
Soluble
Insoluble
Answer:A material that can dissolve in another material called Soluble
Explanation:
Answer:
Option 3.
Soluble is the correct/best answer choice.
A football is kicked with a speed of 18 m/s at an angle of 65° to the horizontal. How far does the football travel horizontally before it hits the ground?
The horizontal distance traveled by the football is determined as 25.33 m.
Horizontal distance traveled by the football
The horizontal distance traveled by the football is calculated as follows;
X = u²sin(2θ)/g
where;
u is the initial speedg is acceleration due to gravityX = (18² x sin(2 x 65))/9.8
X = 25.33 m
Thus, the horizontal distance traveled by the football is determined as 25.33 m.
Learn more about horizontal distance here: https://brainly.com/question/24784992
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Our atmosphere exerts a pressure of 14.7 lb/in2. What is the force on one square foot of the earth’s surface caused by the atmosphere
Answer:
The force on one square foot of the earth’s surface caused by the atmosphere is 101.4 kN.
Explanation:
To force is given by:
[tex]F = P*A[/tex] (1)
Where:
P: is the pressure = 14.7 lb/in²
A: is the area = 1 m²
By entering the above values into equation (1) we have:
[tex]F = P*A = 14.7 \frac{lb}{in^{2}}*\frac{4.45 N}{1 lb}*\frac{1550 in^{2}}{1 m^{2}}*1 m^{2} = 101.4 kN [/tex]
Therefore, the force on one square foot of the earth’s surface caused by the atmosphere is 101.4 kN.
I hope it helps you!
If I push on the wall with 75 Newtons of force, the wall will push back with __
Answer: 0
Explanation:
75 newtons will push back canceling it out make it 0
If I push on the wall with 75 Newtons of force, the wall will push back with 75 Newtons of force.
What is force?Force is defined as a cause which is capable of changing the motion of an object. It can cause an object which has mass to change it's velocity. It is also simply a push or a pull . It has both magnitude as well as direction.Hence, it is a vector quantity.
It has SI units of Newton and is represented by'F'.Newton's second law states that force which acts on an object is equal to momentum which changes with time. If mass of object is constant, acceleration is directly proportional to net force acting on an object.
The concepts which related to force are thrust and torque .Thrust increases the velocity of an object and torque produces change in rotational speed of an object.
Learn more about force,here:
https://brainly.com/question/13191643
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Jason rides his bicycle for 3 hours at a speed to 40 km/h. What distance does he
travel? -
Answer:
120km
Explanation:
What is a unit vector?
A) a vector with all three directions or
dimensions (x,y and z or i, j, k) that are given
B) a vector with only one dimension
C) a vector that has an x and y components that
D) are equal in magnitude
a vector with a magnitude of one
Answer:
A unit vector is (D) a vector with a magnitude of one
Explanation:
Unit Vector Information:
A unit vector is a vector with a magnitude of one. Vectors of different magnitudes can be scaled off the unit vector. Also, they can be used in two, three, or more dimensions.
Other Answers:
A. a vector with all three directions or dimensions that are given
This is the definition of a 3D vector. This is a line segment in three-dimensional space running from point A (tail) to point B (head). Each vector has a magnitude (or length) and direction.
B. a vector with only one dimension
This is the definition of an one-dimensional vector. This type of vector has no dimension, but a number of components, therefore it behaves like a real number.
C. a vector that has an x and y components that are equal in magnitude
(Unsure, I believe this would be defined as an equal vector. Correct me if I'm wrong and I will edit it.)
I hope this helps!
Calculate the force applied (in newtons) if a pressure of 2000Pa is acting on an area of 3m2.
7. Sketch a labeled history graph of a vibrating particle. Be sure to label the axis of the graph correctly, and point out
what qualities of the wave can be determined from the graph.
What are the names of all of the valves in the
heart? Check all that apply
ventricular valve
aortic valve
atrium valve
carotid valve
mitral valve
pulmonary valve
tricuspid valve
Hope this helps:)
can u mark brainiest
Colette launches an air rocket in the upward, positive direction. It launches
with an initial velocity of 25.5 m/s. It accelerates in the downward, negative
direction at a rate of 9.81 m/s2. After 3.5 seconds, what is the magnitude of
the rocket's displacement?
A) 29 meters
B) 31 meters
C) –150 meters
D) 150 meters
Answer:
b
Explanation:
Answer:
The answer is A) 29 meters
Explanation:
I got this question right on the test! :)
Thermal energy can not be transferred or transformed into other forms of energy.
O True
False
Answer:
I believe it is false I took the test
Answer:
false
Explanation:
What do we call the potential mechanical energy stored in an object when work is performed to change its shape?
A.) elastic energy
B.) sound energy
C.) kinetic energy