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 190 m from the crossing
and its spood is 18 m/s.
If the engineer's reaction time is 0.54 m.
what should be the magnitude of the mini-
mum deceleration to avoid an accident?
Answer in units of m/s
The magnitude of the minimum deceleration needed to avoid the accident is –0.89 m/s²
The solution of the question can be obtained by first approaching the relation between Speed, Distance and Time which is given by:
Speed = Distance/Time
Now according to question;
Speed = 18 m/s
Time = 0.54 s
Therefore, Distance = Speed×Time
Distance = 18 × 0.54
Distance = 9.72 m
Thus, the engineer travelled a distance of 9.72 m during the reaction time.
Now, there is a need to find distance between the engineer and the car. This can be obtained by:
Distance between the engineer and the car = Total distance - Distance during the reaction time
Distance between the engineer and the car = 190 – 9.72
Distance between the engineer and the car = 180.28 m
Finally, we need to determine the magnitude of the deceleration needed to avoid the accident. This can be obtained by using newton's third equation of motion, which is represented as:
v² = u² + 2as; where u is the initial velocity, v is the final velocity, a is the acceleration/deceleration and S is the distance.
According to the question;
Initial velocity (u) = 18 m/s
Final velocity (v) = 0 m/s
Distance (s) = 180.28 m
Deceleration (a) =?
Thus, using Newton's third equation of motion
0² = 18² + (2 × a × 180.28)
0 = 324 + 360.56a
=> –324 = 360.56a
=> a = –324 / 360.56
=> a = –0.89 m/s²
Therefore, the magnitude of the deceleration needed to avoid the accident is –0.89 m/s.
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In this circuit diagram, the resistance is 100 ohms, and the current is 0.1 amperes. The voltage is
The required voltage is 10 Volt for 100 ohms of resistance and 0.1 ampere of current.
electric current is defined as the rate at which charge passes a fixed unit cross sectional area.
voltage is defined as the physical quantity required to move charge from one end to other.
Resistance is defined as the the factor opposing electric current.
Ohms law states that voltage is directly proportional to electric current
V=IR
given:
current (I) = 0.1 A
resistance (R)=100 ohms
now from definition of voltage we have:
V=I.R
V=100×0.1
V=10volts
therefore the required voltage is 10 volts.
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2. Link walks 5 miles east, then 7 miles north, than 2 miles south.
a) What distance did he travel? What is his displacement?
b) Suppose Link made the whole journey in 4 hours. What was his average speed and
average velocity during his journey?
Link walks 5 miles east, then 7 miles north then 2 miles south
If you draw a simple diagram you’ll see that your displacement from the start is 5 miles East and 7 miles North and then 2 miles south
These distances are the sides of a right-angled triangle. The displacement you are looking for is the hypotenuse of the triangle. Use the Pythagorean theorem to calculate it.
Displacement
= √ (5+2)^2 + 7^2)
= 9.899 miles
Distance
= 5+7+2
= 14 miles
Time to complete his whole journey = 4 hours
Average Speed= Distance travelled / Time
= 14÷4
= 3.5 miles/hour
Average velocity= Displacement / Time
= 9.899÷4
= 2.47475 miles/hour
The distance is 14 miles and the displacement is 9.899 miles, the Average Speed is 3.5 miles/hour and the Average Velocity is 2.47475 miles/hour
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A car traveling 83.0 km/h on a straight road is 1900 m behind a truck traveling at 61.0 km/h . How much time will it take the car to catch up with the truck?
A car traveling 83.0 km/h on a straight road is 1900 m behind a truck traveling at 61.0 km/h. The required voltage is 10 Volts.
What is Electric Current ?Electric current is defined as the rate at which charge passes a fixed unit cross sectional area.
What is Voltage ?Voltage is defined as the physical quantity required to move charge from one end to other.
What is Resistance ?Resistance is defined as the the factor which opposed the electric current.
It states that voltage is directly proportional to electric current
V=IR
Given:
current (I) = 0.1 A
resistance (R) = 100 Ω
Now from definition of voltage we have:
V = I × R
V = 100 × 0.1
V = 10 volts
Thus from the above conclusion we can say that therefore the required voltage is 10 volts.
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WILL GIVE BRAINLIEST!!!!!!!
why would astronomers make the planets line up in a straight line on a model?
Two ropes are attached to a heavy object. The ropes are given to two strong physics students (is there any other kind?) with instructions for each to pull with 1000 N of force. Determine the resultant force if the two students pull: a) in the same direction east.
What is the speed over the ground mosquito flying 2 m/s relative to the ar caught in a 2 m/s right angle crosswind
The speed over the ground is 0 m/s.
The speed of an object or body is the magnitude of the change of its position over time or the magnitude of the change of its position per unit of time; it is thus a scalar quantity.
As it is given that the mosquito is flying at 2 m/s relatives to the air caught in a 2 m/s right angle crosswind.
As we know that speed over the ground is the difference between the flight speed and resistance speed.
So, the general equation for the speed over the ground is :
v = Flight Speed of the mosquito - Resistance Speed of the crosswind
This implies, [tex]v= 2 {~}m / s - 2{~} m / s[/tex]
[tex]v = 0 {~}m / s[/tex]
Hence, the speed over the ground is 0 m/s.
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What kinds of materials can be involved in static electric effects?
All types of materials, both metals and non metals
Only metals but not non-metals
Only non metals but not metals
Only certain metals but not all metals and not non-metals
Only certain metals and certain non-metals
The kinds of materials can be involved in static electric effects is All types of materials, both metals and non metals.
What is static electric effects?The static electric effects can be described as the effect that bring about the changes to the body as a result of the changes in the distribution that is been imposed on the electric charges that is found on the surface of the body.
It should be noted that sufficiently large surface charge density could be discovered as a result of the effect, however in the case above option A is correct.
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Which of the following best describes a position versus time graph foran accelerating object?
Answer: I don't really see the answer choices.
Explanation:
You drop a 20 Ton object and a
10 Ton object at the same time.
How does the acceleration
compare through the fall
assuming minimal air resistance.
Explanation:
it dosent depend on the weights of the items. I'll reach the ground at same time taking as no air friction or restrictions.
i.e
v = u + gt
whte v is final velocity of the object
u is initial velocity of the object
g is acceleration due to gravity and
t is time. thanks
please if found helpful rate brainliest
Assuming there is little air resistance, the acceleration felt by both objects when one drops a 20-ton object and a 10-ton object at the same time will be the same.
Even though both objects accelerate at the same rate, the forces acting on them will be different because of their different masses. Newton's second law of motion states that an object's force is inversely proportional to its mass (F = ma). The 20-ton object will therefore encounter twice as much force as the 10-ton object, but their rates of acceleration will remain constant.
In conclusion, both the 20-ton and 10-ton objects will accelerate to about 9.8 meters per second squared when dropped simultaneously with little air resistance.
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What is the condition for block b to move downwards
A) mb/ma > sin theta - mew cos theta
B) mb/ma > cos theta + mew sin theta
C) mb/ma > sin theta + mew cos theta
D) mb/ma > cos theta - mew sin theta
And what would the condition for the block to move upwards
A) mb/ma < sin theta - mew cos theta
B) mb/ma < cos theta + mew sin theta
C) mb/ma < sin theta + mew cos theta
D) mb/ma < cos theta - mew sin theta
Answer:
Solution in Photo
Explanation:
To solve this question, draw the Free Body Diagram (FBD) for the whole system such that
theta < 90, it will be more clearer that way.
PLEASE help me with this problem??!!
2. A radiographic technique calls for a 400 mA, 1/30s exposure. What is
the mAs?
Answer:
13.33 mA s
Explanation:
400 mA * 1/30 s = 13.33 mA s
A stone of mass 6.74kg is dropped from rest at a height of 6.02m. What impulse does gravity impart to this stone from the instant is dropped until it hits the ground, assuming negligible air resistance?
The impulse the gravity imparts on the stone from the instant it was dropped until it hits the ground is 72.66 Ns
What is impulse?
This is defined as the change in momentum of an object.
Impulse = change in momentum
Impulse = final moment – Initial momentum
Impulse = force × time
How to determine the timeInitial velocity (u) = 0 m/sAcceleration due to gravity (g) = 9.8 m/s²Height (h) = 6.02 mTime (t) =?h = ½gt²
6.02 = ½ × 9.8 × t²
6.02 = 4.9 × t²
Divide both side by 4.9
t² = 6.02 / 4.9
Take the square root of both side
t = √(6.02 / 4.9)
t = 1.1 s
How to determine the impulseTime (t) = 1.1 sMass (m) = 6.74 kgAcceleration due to gravity (g) = 9.8 m/s²Force (F) = mg = 6.74 × 9.8 = 66.052 NImpulse =?Impulse = Force × time
Impulse = 66.052 × 1.1
Impulse = 72.66 Ns
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What are the reasons Flat Earther's use to prove their claim?
Answer:
The ground we walk on is flat, not round. Gravity doesn't exist. Objects don't fall down, the flat earth(disk) goes up with a force called dark energy. There is a 45 ft tall ice wall to prevent people from falling off the Earth.
Explanation:
An astronaut has left the space shuttle on a tether to test a new personal maneuvering device. She moves
along a straight line directly away from the shuttle. Her onboard partner measures her velocity before and
after certain maneuvers, and obtains the following results:
A. VL = 0.8 m/s,
B. U 1.6 m/s,
C. U = -0.4 m/s,
U2x = 1.2 m/s; (speeding up)
U2x = 1.2 m/s; (slowing down)
v₂x = -1.0 m/s; (speeding up)
D. U-1.6 m/s,. U2x = -0.8 m/s. (slowing down)
If t₁ = 2 s and t₂ = 4s in each case, find the average acceleration for each set of data.
(a) The acceleration is 0.2 m /s²
(b) The acceleration is - 0.2 m /s²
(c) The acceleration is - 0.3 m /s²
(d) The acceleration is 0.4 m /s²
Acceleration is outlined as The rate of amendment of rate with relevancy time.Acceleration could be a vector amount because it has each magnitude and direction. it's additionally the second by-product of position with relevancy time or it's the primary by-product of rate with relevancy time which is given by a = v₂ₓ - v₁ₓ / t₂ - t₁ .......(1) equation (1)(a) Putting v₁ₓ = 0.8 m/s , v₂ₓ = 1.2 m/s , t₁ = 2 s and t₂ = 4s in equation (1)
, we get a = 1.2 - 0.8 / 4 -2
a = 0.4 / 2
a = 0.2 m /s²
(b) Putting v₁ₓ = 1.6 m/s, v₂ₓ = 1.2 m/s , t₁ = 2 s and t₂ = 4s in equation (1) , we get a = 1.2 - 1.6 / 4 -2
a = - 0.4 / 2
a = - 0.2 m /s²
(c) Putting v₁ₓ = - 0.4 m/s, v₂ₓ = - 1.0 m/s, t₁ = 2 s and t₂ = 4s in equation (1) , we get a = -1.0 - (-0.4) / 4 -2
a = - 0.6 / 2
a = - 0.3 m /s²
(d) Putting v₁ₓ = -1.6 m/s, v₂ₓ = -0.8 m/s, t₁ = 2 s and t₂ = 4s in equation (1) , we get a = -0.8 - (-1.6) / 4 -2
a = 0.8 / 2
a = 0.4 m /s²
The traveller races in cases (a) and (c) and slows down in (b) and (d), however the common acceleration is positive in (a) and (d) and negative in (b) and (c). In alternative words, negative acceleration doesn't essentially indicate a deceleration down.
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The complete question is given below :
An astronaut has left the space shuttle on a tether to test a new personal maneuvering device. She moves along a straight line directly away from the shuttle. Her onboard partner measures her velocity before and after certain maneuvers, and obtains the following results:
(a) v₁ₓ = 0.8 m/s, v₂ₓ = 1.2 m/s; (speeding up)
(b)v₁ₓ = 1.6 m/s, v₂ₓ = 1.2 m/s; (slowing down)
(c) v₁ₓ = - 0.4 m/s, v₂ₓ = - 1.0 m/s; (speeding up)
(d) v₁ₓ = -1.6 m/s, v₂ₓ = -0.8 m/s; (slowing down)
If t₁ = 2 s and t₂ = 4s in each case, find the average acceleration for each set of data.
If a balloon with a weight of 3000 N (306kg) is lifted by an air force of 3300 N, in what will be its acceleration?
Answer:
See below
Explanation:
F = ma net force is 300 N upward
300 = 306 * a a = .980 m/s^2
Determine the upward applied force, in lbf, required to accelerate a 4.5-lb model rocket vertically upward, with an acceleration of 3 g’s. The only other significant force acting on the rocket is gravity, and 1 g 5 32.2 ft/s2.
The upward applied force will be 579.249 lbf.
Mass of the rocket, m = 4.5 lb
Acceleration, a = 3g
as we know g = 32.2 ft/s²
therefore acceleration, a = 3 * 32.174 = 96.522 ft/s²
According to the Newton's second law of motion, which states that the magnitude of the force acting on an object is equal to the product of the object's mass and the acceleration with which it is moving.
Mathematically, it is F = [tex]\frac{mass}{acceleration}[/tex] ;
Upward force (F₀) for the rocket will be the sum of Force applied by the weight (Fₓ) and the force by the acceleration(Fₐ).
i.e. gₙ *F₀ = Fₓ + Fₐ
Fₓ = mg
Fₐ = ma
F₀ = ma + mg
F₀ = m (a + g)
F₀ = 4.5 (96.522 + 32.2)
F₀ = 4.5 * 128.722
F₀ = 579.249 lbf.
The upward applied force, required to accelerate a 4.5-lb model rocket vertically upward will be 579.249 lbf.
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World should shift its energy dependence from nonrenewable sources to renewable sources. Write your opinion
Answer:
•Renewable energy, often referred to as clean energy, comes from natural sources or processes that are constantly replenished. For example, sunlight or wind keep shining and blowing, even if their availability depends on time and weather.
• Renewable sources of energy are better than nonrenewable sources because they refill themselves over a short period of time.
A model shows that the moon has grown to twice its size yet has remained in the same place and one or two sentences explain how this would impact the gravity between earth and the moon?
The attractive force of Earth on the moon will be said to be double when there is a doubling of the mass of the moon.
Since the moon has an attracting force, it is one that will remain the same on Earth. In gravitational forces, the two concerned objects always feel the same force.
What would occur to the gravitational pull between Earth and moon if the moon were twice as large?The explanation of how this would affect the gravity between earth and the moon is that this can result to the earth tilt a little bit harder to change, which could imply that there will be a more stable climate and ice ages may not occur as often.
Therefore, The attractive force of Earth on the moon will be said to be double when there is a doubling of the mass of the moon. Since the moon has an attracting force, it is one that will remain the same on Earth. In gravitational forces, the two concerned objects always feel the same force.
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Giving Brainliest!
Temperature is a vector quantity because it can go down as well as up. True or false?
Answer:
Explanation:
temperature is a scalar quantity
A rescue helicopter lifts a 50kg rock climber. If he accelerates at 5m/s what is the tension of the rope
The tension of the rope is 750 N.
According to Newton's second law of motion, the mass of a rock climber, m = 50 kg, while lifting a thing upwards with an acceleration, the upward force must be larger than the weight of the object in order to have a net force in upward direction to induce acceleration in upward direction.
accelerating a rock climber upward with a rope,
a= 5 m/s
determining the rope's tension (T)
The following two forces are at work on the rock climber as it is raised:
Rope tension acting upward. The rock climber's weight acting downward. Using Newton's second rule of motion, we may now:
Mass times climber's acceleration equals net upward force.
T−m×g=m×aT
=m×(g+a)T
=50× (10+5) T
=750 N
The complete question is -A rescue helicopter lifts a 50 kg rock climber by a rope from a cliff face. The rock climber is accelerated vertically a 5m/s−² What is the tension in the rope?
a) 350N
b) 500N
c) 750N
d) 1500 N
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A ball dropped from a window strikes the ground at 4.00 s later. How high is the window above the ground?
Answer:
15
Explanation:
During weather that may produce freezing temperatures, Florida orange growers often spray water on their orchards to protect them. Which of the following best explains why this helps protect orange trees and fruit from freezing?
The statement that best explains why this helps protect orange trees and fruit from freezing is that the transfer of thermal energy in water as it freezes protects the orange trees by transferring heat energy from the orange trees and fruit. That is option A.
What is freezing?Freezing is the phase transition that involves the change of a liquid substance into a solid form as it's temperature becomes lower.
During winter seasons which is a weather that can freez the orange fruits, the orange grower sprays water on their orange trees to prevent it from freezing.
The mechanism that prevents the orange from freezing is the transfer of the thermal energy between the water and the orange fruits.
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a half meter ruler is pivoted at its midpoint and balances whaen a weight of 20N is placed at the 10 cm mark and a weight W is placed at the 45 cm mark on the ruleer. Calculate the weight W
Answer:
35
Explanation:
If f(x) = 2x - 8 and g(x) = x4, what is (g°f)(5)?
080
Clear all
Enter the correct answer.
I
+00
DONE
6 of 15
Exit
The correct answer is 16.
The conventional way to express function is F(x).
You may alternatively describe it as a machine that has input, output, and some other ways they are connected.
You must first evaluate the first function in order to get the value of a composite function like this one. We placed the value for x in parentheses first in that equation because f is on the right side.
f (x) = 2x - 8
f (5) = 2 × 5 - 8
f (5) = 10 - 8
f (5) = 2
Once the first portion of a composite function has an answer, we insert that response into the second part. We insert our response (2) into g because it is on the left side.
g(x) = x^4
g(2) = 2^4
g(2) = 16
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How large is a neutrino?
1 picometer
1 gigameter
1 yoctometer
1 nanometer
1. A 10kg ball moving at a speed of 6 m/s strikes another 5kg ball at rest with a contact time of 0.5 seconds. The 10kg comes to a complete stop. (a) What average force was exerted on the 10kg ball? (b) What average force was exerted on the 5kg ball? (c) What is the final momentum of the 5kg ball? (d) What is the initial momentum of the 10kg ball?
a)average force was exerted on the 10kg ball= -120 N
b)average force was exerted on the 5kg ball= 60N
c)What is the final momentum of the 5kg ball= 2.5 kg m/s
d) the initial momentum of the 10kg ball=60 kg m/s
The average force can be calculated by formula F=m(vf–vi)/ Δt so, 10 (0-6)/0.5 = -120 N the minus is representing opposite direction
the average force on the 5 kg ball = 5(6-0)/0.5= 60 N
The final momentum of 5 kg ball is 5 X 0.5 =2.5 kg m/s and initial momentum of 10 kg ball = 10 X 6 = 60 Kg m/s.
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What can develop when the temperature of the ocean is 80°F. A. Tornado B. Tsunami C. Thunder Storm D. Hurricane
When the temperature of the ocean is 80°F what is likely to develop is Hurricane. That is option D.
What is Hurricane?Hurricane is a natural disaster that occurs over the tropical large water bodie such as the oceans which is characterized by low-pressure storm.
The factors that can cause the occurrence of hurricane include the following;
Increase in Ocean temperature: waters above 80 degrees Fahrenheit provide energy for a hurricane to form.Water movement: spinning in low-pressure areas of water creates a wave.Low wind shear : low wind shear allows a storm to grow large and strong.Therefore, when the temperature of the ocean is 80°F what is likely to develop is Hurricane.
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Answer: thunderstorm
Explanation:
When the sea surface is at least 80° Fahrenheit (27° Celsius), it can supercharge a thunderstorm. The storm sucks up that heat and water, which make the storm bigger. As it grows, air pressure at the center of the storm continues to drop, which causes the vacuum in the middle to grow stronger.
An object starts from rest and undergoes uniform acceleration. From 3.44s to 9.49s it travels 2.9m. What is the average velocity of the object during the time interval 18.6s to 22.92s (in m/s )?
First, see that in the time interval 3.44 to 9.49, the average velocity is [tex]2.9\text{m} / (9.49\text{s} - 3.44\text{s})=2.9\text{m}/6.05\text{s} \approx 0.479\text{m/s}[/tex]. So, as we have uniform acceleration, the velocity must be linearly increasing over this entire interval, so for the average to be 0.479 m/s over this interval, the velocity must be 0.479 m/s in the exact middle of this interval, or at 5.465s.
We now note that the object starts from rest, which means that at 0s, the velocity is 0 m/s. So, in 5.465 seconds, the velocity increases by 0.479 m/s. We again have that the object undergoes uniform acceleration, meaning that the acceleration over this interval is a constant [tex]\frac{0.479\text{m/s}}{5.465\text{s}} \approx 0.0876 \text{m/s}^2[/tex].
Finally, note again that as we are looking at uniform acceleration, by the same principle at the beginning, the average velocity of the object during the time interval from 18.6s to 22.92s is the same as the velocity at the exact middle of this interval, or at 20.76s. We have that acceleration is constant and 0.0876 m/s^2, and initial velocity is 0 at 0s. So, in 20.76 seconds, the object will have accelerated [tex]0.0876\text{m/s}^2 \cdot 20.76\text{s} \approx 1.82 \text{m/s}[/tex].
So, average velocity will be 1.82 m/s over the time interval 18.6s to 22.92s.