Answer: -2m/s²
Explanation:
Each second, the acceleration decreases of 2m/s²
N.B.: in physics, deceleration is also acceleration.
a 1200-kg pick-up truck traveling south at 15 m/s suddenly collides with a 750-kg car that is traveling east. the two vehicles stick together and slide along the road after colliding. a highway patrol officer investigating the accident determines that the final position of the wreckage after the collision is 25 m, at an angle of 50° south of east, from the point of impact. she also determines that the coefficient of kinetic friction between the tires and the road at that location was 0.40. what was the speed of the car just before the collision?
The conservation of momentum, Newton's second law and kinematics allows to find the result for the initial speed of the car is:
The speed of the car is 40 m/s at the East direction.
Given parameters
Mass of the truck M = 1200 kg. Truck speed v₀₁ = 15 m / s towards the South. Mass of the car m = 750 kg. Travel east The two vehicles unite. The braking distance d = 25m at 50º SE The friction coefficient μ = 0.40To find
The initial speed of the car.
The momentum is defined by the product of the mass and the velocity of the body, so it is a vector quantity. In the case of an isolated system the momentum is conserved.
In the attachment we see a diagram of the vehicle crash, let's write the moment for each axis.
y-axis
Initial instant. Before the shock.
[tex]p_{oy}[/tex] = M v₀₁
Final moment. After the crash
[tex]p_{fy}[/tex] = (M + m) [tex]v_{fy}[/tex]
The system is formed by the two vehicles for which during the crash it is isolated and the momentum is conserved.
[tex]p_{oy} = p_{fy} \\\\M v_{o1} = (M+m) v_{fy} \\v_{fy} = \frac{M}{M+m} \ v_{o1}[/tex]
Calculate us
[tex]v_{fy} = \frac{1200}{1200+750} \ 15[/tex]
vfx = 9.23 m / s
x-axis
Initial instant. Before the crash.
p₀ₓ = m v₀₂
Final moment. After the crash.
[tex]p_{fx}[/tex] = (M + m) [tex]v_{fx}[/tex]
The momentum is preserved.
[tex]p_{ox}= p_{fx} \\m v_{o2) = (M+m) \ v_{fx}[/tex]
Let's find the velocity just after the collision, let's use Newton's second law,
y-axis
N-W = 0
N = W = (M + m) g
x-axis
fr = (M + m) a
The friction force is the macroscopic manifestation of the interactions between the two bodies.
fr = μ N
We substitute.
μ g = a
Now we can use kinematics.
v² = v₀² - 2a d
When the vehicles stop their speed is zero.
v₀² = 2 a x
v₀ = [tex]\sqrt{2\ \mu \ g \ d}[/tex]
Let's calculate.
v₀ = [tex]\sqrt{2 \ 0.40 \ 9.8 25 }[/tex]
v₀ = 14 m / s
This is the speed of the two vehicles just after the collision, that is, let's use trigonometry to find their components.
cos 25 = [tex]\frac{v_{ox}}{v_o}[/tex]
v₀ₓ = v₀ cos 25
v₀ₓ = 14 cos 25
v₀ₓ = 12.69 m / s
We substitute in the expression of the conservation of the momentum in the x-axis.
m v₀₂ = (M + m) [tex]v_{fx}[/tex]
[tex]v_{o2} = \frac{M+m}{m} v_{fx}[/tex]
Let's calculate.
[tex]v_{o2} = \frac{1200+750}{750} \ 12.69[/tex]
vfy = 32.99 m / s = 40 m / s
In conclusion using the conservation of momentum, Newton's second law and kinematics we can find the result for the initial speed of the car is:
The speed of the car is 40 m/s at the East direction.
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Two towers of height 40 m and 30 m respectively support a transmission line conductor at water crossing. The horizontal distance between the towers is 300 m. If the tension in the conductor is 1590 kg, find the clearance of the conductor at a point mid-way between the supports. Weight of conductor is 0·8 kg/m. Bases of the towers can be considered to be at the water level.
The sag in the tensioned cable depends on the weight of the cable and
the applied tension.
The clearance midway between the support is approximately 29.34 metersReasons:
The given parameters are;
Height of the towers are; h₁ = 40 m and h₂ = 30 m
Horizontal distance between the towers, l = 300 m
The tension in the conductor, T = 1,590 kg
Weight of the conductor, w = 0.8 kg/m
Required:
The clearance space of the conductor mid-way between the support
Solution:
The distance, x₁, to the lowest point on the conductor, from the tower, h₁, is given by the formula;
[tex]\displaystyle x_1 = \mathbf{ \frac{l}{2} -\frac{T \cdot h}{w \cdot l}}[/tex]
Where;
h = h₂ - h₁ = 40 m - 30 m = 10 m
Which gives;
[tex]\displaystyle x_1 = \frac{300}{2} -\frac{1590 \times 10}{0.8 \times 300} = \mathbf{83.75}[/tex]
The sag at the lowest point is give by the formula;
[tex]\displaystyle d_1 = \mathbf{ \frac{W \cdot x_1^2}{2 \cdot T}}[/tex]
Therefore;
[tex]\displaystyle d_1 = \frac{0.8 \times 83.75^2}{2 \times 1590} = \frac{4489}{2544} \approx 1.765[/tex]
The lowest point sag, s₁ = 30 m - 1.765 m = 28.235 m
The distance of the midpoint from the lowest point, x, is therefore;
[tex]\displaystyle x = \frac{l}{2} - x_1 = \frac{300}{2} - 83.75 = \mathbf{ 66.25}[/tex]
Which gives;
[tex]\displaystyle d_x = \frac{0.8 \times 66.25^2}{2 \times 1590} = \frac{53}{48} \approx 1.104[/tex]
The clearance midway between the support ≈ 28.235 + 1.104 ≈ 29.34
The clearance midway between the support ≈ 29.34 m
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A catamaran with a mass of 5.44×10^3 kg is moving at 12 knots. How much work is required to increase the speed to 16 knots? (One knot = 0.51 m/s.)
show all steps
The work that is required to increase the speed to 16 knots is 14,176.47 Joules
If a catamaran with a mass of 5.44×10^3 kg is moving at 12 knots, hence;
5.44×10^3 kg = 12 knots
For an increased speed to 16knots, we will have:
x = 16knots
Divide both expressions
[tex]\frac{5.44 \times 10^3}{x} = \frac{12}{16}\\12x = 16 \times 5.44 \times 10^3\\x = 7.23\times 10^3kg\\[/tex]
To get the required work done, we will divide the mass by the speed of one knot to have:
[tex]w=\frac{7230}{0.51}\\w= 14,176.47Joules[/tex]
Hence the work that is required to increase the speed to 16 knots is 14,176.47 Joules
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in terms of the wavelength of the sound wave, about how far below the open end of the resonance tube is the first resonant position?
The first resonant position below the open end of the resonance tube is; one-quarter of the wavelength
In the event of the first resonant position in a resonance tube, there will be a maximum air displacement which is only one antinode right at the open end where the motion is constrained.
However, there will be no displacement at the closed end which means another one node right at the closed end where air is halted.
This means that the standing wave will have one-quarter of the wavelength in the test tube.
Thus;
L = ¼λ
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b. Ron bicycles forward with an acceleration of 2.1 m/s2. If he is applying a forward force of 195 N, what is his mass?
Answer:
92.86 kgExplanation:
lThe mass of an object given only it's force and acceleration can be found by using the formula
[tex]m = \frac{f}{a} \\ [/tex]
f is the force
a is the acceleration
From the question
f = 195 N
a = 2.1 m/s
We have
[tex]m = \frac{195}{2.1 } = 92.857142... \\ [/tex]
We have the final answer as
92.86 kgHope this helps you
During a collision, a 63.9-kilogram driver of a car moving at 24 m/s is brought to rest by an inflating airbag in 1.2 seconds. What is the magnitude of the force exerted on the driver by the airbag?
Hi there!
We can use impulse for this situation:
I = Δp = mΔv
Impulse = Force × time, so:
I = 63.9(24) = 1533.6 Ns
Find force by dividing by time:
I/t = 1533.6/1.2 = 1278 N
What is the instruments used to measure light intensity, wind intensity and relative humidity
Answer:
we use : photometer to measure light intensity
:Anemometer to measure wind intensity
:Hygrometer to measure relative humidity
A moving object is in equilibrium. Which best describes the motion of the object if no forces change?
It will change directions.
It will slow down and stop.
It will maintain its state of motion.
It will speed up and then slow down.
Answer:
it is It will maintain its state of motion. because of newtons law states that any object in morion will stay in motion unless acted upon another force pushing against it
Explanation:
Answer:
It will maintain its state of motion.
Explanation:
An object is at rest. There are several forces acting on the object, but the net force is zero. If all the
forces acting on the object were to suddenly double in size, would the object start moving? Why or why not?
Answer:
no
Explanation:
because the heaver an object the harder it is to move s the force will not be able to move it
how do humans affect the lithosphere
when you hold a spherical concave mirror with a 48.2-cm radius of curvature in front of your face, you see an image of your face that is 61.8 cm in front of the mirror. what is the distance between the mirror and your face?
The distance between the mirror and your face is 39.5 cm
Using the mirror formula 2/r = 1/u + 1/v where r = radius of curvature = - 48.2 cm, u = distance between mirror and your face = object distance and v = distance between image and your face = - 61.8 cm. The distances are negative since the image is in front of the mirror and distances to the left of the mirror are negative.
So, making u subject of the formula, we have
2/r = 1/u + 1/v
1/u = 2/r - 1/v
1/u = (2v - r)/rv
u = rv/(2v - r)
Substituting the values of the variables into the equation, wse have
u = -48.2 cm × -61.8 cm/(2 × -61.8 cm - (-48.2 cm))
u = 2978.76 cm²/(-123.6 cm + 48.2 cm)
u = 2978.76 cm²/-75.4 cm
u = -39.51 cm
u ≅ -39.5 cm (The distance is negative since it is in front of the mirror)
So, the distance between the mirror and your face is 39.5 cm
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How does the electric energy between two negativly charged particles change if one particles charge is increased by a factor of 2
Answer:
i dont know this one
Explanation:
sorry i wish i could help but if u look closley on that qyestion you will understand it mor
When the atmosphere is absolutely unstable, the environmental lapse rate is ________ the dry adiabatic lapse rate.
Answer: greater than
Explanation:
(50 POINTS!!) 3. Make a model that shows the forces acting on two blocks on a flat, frictionless surface:
a. A 1 N block at rest
b. A 1 N block with 2 N of force applied in one horizontal direction
Include arrows to represent the forces and labels to indicate the magnitude of each force. Use your model to compare and explain the motion of each block.
The change in position of an object is known as motion. Force is external that causes a body to change its position
For a body is to be at rest, the sum of all the forces acting on the object must be zeroFor a 1N block to be at rest, the normal force acting opposite to the weight must also be 1N.For 1 N block with 2 N of force applied in one horizontal direction, the image of the body is as shown in the attachmentLearn more about force here: https://brainly.com/question/20955770
Answer:
In short terms. the 1N block at rest will stay still and the 1N block with 2N applied will move forward.
What is the acceleration as an object goes from +20 m/s to +26 m/s over 1.4 s?
Answer:
4.3 m/s^2
Explanation:
a = vf - vi / t
26 - 20 / 1.4
= 4.28 ( round your numbers)
The mercury in a barometer of a cross-sectional area 1 cm² stands at 75 cm, and the space above it is 9 cm in length. What
volume of air, measured at 3. The mercury in a barometer of a cross-sectional area 1 cm² stands at 75 cm, and the space above it is 9 cm in length. What
volume of air, measured at atmospheric pressure, would have to be admitted into the space to cause the column of the mercury
to drop to 59 cm?
The ideal gas equation and the pressure in barometer allows us to find the amount of air that we must introduce into the barometer for the change in height of the mercury column is:
The variation of the volume is: ΔV = 7.67 cm³
Pressure is defined by the relationship between force and area.
P = F / A
The ideal gas equation establishes a relationship between pressure, volume, and temperature of an ideal gas.
PV = nR T
Where P is pressure, V is volume, and T is temperature.
Let's write this equation for two points assuming that the temperature has not changed.
P₀ V₀ = P₁ V₁
V₁ = [tex]\frac{P_o}{P_1} \ V_o[/tex] (1)
The subscript "o" is used for the start point and the subscript "1" for the end point.
The pressure in a barometer is:
P = ρ g y
They indicate the initial height of the barometer y₀=75 cm, the distance from empty space y'₀ = 9 cm and the final height of the barometer y₁ = 59 cm.
The volume of the cylinder is
V = π r² y
Let's calculate the initial volume.
V₀ = π 1 9
V₀ = 28.27 cm³
We substitute in equation 1.
V₁ = [tex]\frac{\rho \ g \ y_o}{\rho \ g \ y_1} \ V_o[/tex]
V₁ = [tex]\frac{y_o}{y_1} \ V_o[/tex]
Let's calculate.
V₁ = [tex]\frac{75}{59} \ 27.27[/tex]
V₁ = 35.94 cm³
The volume to be incremented is
ΔV = V₁ - V₀
ΔV = 35.94 - 28.27
ΔV = 7.67 cm³
Using the ideal gas equation and the pressure in barometer we can find the amount of air that we must introduce into the barometer for the change in height of the mercury column is:
The change of the volume is: ΔV = 7.67 cm³
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A student did 24 J of work on a chair. She applied a force of 12 N and moved the chair 2 m. What else do you need to know to determine the amount of power used?
Answer:
time
Explanation:
power = work done ÷ time
Help meeeeeeeeeeeeee
An "energy bar" contains 26 ggof carbohydrates.How much energy is this in joules?
An escalator in a busy shopping centre lifts people up from one floor to another. This takes 1.2 MJ every minute. What is the power output of the escalator motor? Give your answer in kW.
An escalator that takes 1.2 MJ every minute has a power output of 1200 kW.
An escalator used to lift people up from one floor to another, exerts a work (w) of 1.2 MJ in 1 minute (t).
In physics, power (P) is the amount of energy (w) transferred or converted per unit time (t).
[tex]P = \frac{w}{t} = \frac{1.2 \times 10^{6} J }{1min} = 1.2 \times 10^{6} W[/tex]
We can convert 1.2 × 10⁶ W to kW using the conversion factor 1 kW = 1000 W.
[tex]1.2 \times 10^{6} W \times \frac{1kW}{1000W} = 1200kW[/tex]
An escalator that takes 1.2 MJ every minute has a power output of 1200 kW.
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Daniel is 50.0 meters away from a building. He observes that his line-of-sight to the tip of the building makes an angle of 63.0° with the horizontal. What is the height of the building?
Answer:
willie tower
Explanation:
mataas kasi
When astronomers carefully examine the planets found by Kepler and draw conclusions from the Kepler sample, what do they conclude about planets the size (radius) of Earth
Given what we know about the Kepler space program, we know that the astronomers discovered that Earth-sized planets are more common than we imagined.
Kepler was launched with the intention of getting a closer look at other planets outside of our solar system using enhanced photometrics.
The idea behind this launch was to discover more Earth-sized planets, preferably within the habitable zone of their central star.
What this mission showed astronomers, is that Earth-sized planets are more common than we could have imagined, Kepler proved this by finding over 2,662 planets to date.
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A crane lifts a 10000 N load through a distance of 30mins in 40s calculate work done
Given,
Force = 10,000 N
Distance = 30 m
Time = 40 s
Work done = force × distance
Work = 10,000 × 30
Work = 300,000 J
______
꧁✿ ᴿᴬᴵᴺᴮᴼᵂˢᴬᴸᵀ2222 ✬꧂
The work done on the object is equal to the power it experiences which is equal to 735 watts.
What is work done?Work done is defined as the product of force applied and the distance over which the force is applied on the object. Work is done on an object when a force is applied to an object and the object is moved through a particular distance.
The time rate of doing work is called as power, which is designated by the symbol P. It is measured in the units of watts, where one watt is equal to one joule energy applied per second time.
Work done on an object is equal to the force (F) multiplied by the distance d in the direction of the force. Where, time interval is Δt.
P = W/Δt = F × d/Δt = m × g × h/Δt = 100 × 9.8 × 30 / 40
Power = 735 watts
The power of the object is 735 watts.
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The angular quantities L, omega, and alpha are vectors. The vectors point along the axis of rotation with a direction determined by __________.
The vectors point along the axis of rotation with a direction determined by an arrow.
What is a vector?There are two types of physical quantity one is a scaler and another one is a vector.
The quantity that requires only megnitude to define is known as the scalar quantity. While the vector quantities need both megnitude and the direction to define.
The vector quantity is represented by an arrow. The vectors point along the axis of rotation with a direction determined by an arrow.
The angular quantities L, omega, and alpha are vector quantities.
Hence arrow is the correct answer for the blank.
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The direction of the vectors of angular momentum and L, angular velocity omega and the mass alpha is determined using the right hand rule.
What is right hand rule?Righthand rule in physics states that, when we curl our right hand fingers, the direction of the angular momentum and velocity will be in the direction of thumb and curl of fingers determine the axis of rotation.
Angular momentum is a vector quantity defined as the product of moment of inertia and angular velocity where, the angular velocity ω is the rotational analogue of linear velocity i.e.. product of the linear velocity and radius of rotational path.
Therefore, the angular quantities L, angular velocity ω along the axis of rotation can be determined using the right hand rule. Where direction of thump represents the direction of vector components.
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when light reflects from a surface, there is a change in its
When light reflects from a surface, there is a change in its intensity. Thus, the correct option is C.
What is Light intensity?Light intensity is also known as luminous intensity. It is the amount of light which is falling on a surface over any given square foot or square meter in size. Light intensity can be measured in terms of lumens per square foot (foot candles) or lumens per square meter (lux).
Light intensity is affected by various factors such as surface on which the light rays strike, the medium, reflection, and the refraction of light.
When a ray of light reflects from a surface, there is a change in the intensity of light and also the speed of light in that medium.
Therefore, the correct option is C.
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Your question is incomplete, most probably the complete question is:
When light reflects from a surface, there is a change in its:
a. frequency
b. velocity
c. intensity
d. phase
A car starts from rest and accelerates at 2.5m/s^2 for 2s. What is the final velocity of the car
Answer:
5m/s ez
Explanation:
plz make me brainliest
an object initially moving with 12m/s accelerates uniformly by3m/s^2 for 10 seconds how far does it travel in first 7 seconds
Answer:
157.5
Explanation:
X=vi *t + 0.5*a*t^2
vi=12, t=7, a=3
x= 12*7 + 0.5*3*7^2
= 84+ 73.5= 157.5 m
Help help fast please first answer gets brainiest also needs to be clearly stated
What would be the acceleration of a block sliding down an inclined plane that makes an angle of 45° with the horizontal if the coefficient of sliding friction between two surfaces in 0.3? 141
Ans: 4.95 m/sec?
Answer:
unfortunately we have not received a reply to the park yet but
Explanation:
mohamedz and he had killed him
When we use an analogy that represents the expanding universe with the surface of an expanding balloon, what does the inside of the balloon represent?
Answer: When we use an analogy that represents the expanding universe with the surface of an expanding balloon, what does the inside of the balloon represent? The inside of the balloon does not represent any part of our universe.
