Answer:
A) Δf = - 49 m, B) v (7) = -56 m / s, a = - 8 m / s², C) t = 0.866 s
Explanation:
A) In this exercise ask to find the displacement and the average velocity, give the function of the movement
f (t) = - 4t² +3
and the range of motion 0≤ t ≤ 7
the displacement is
for t = 0
f (0) = 3
for t = 7 s
f (7) = - 4 7² +3
f (7) = -46 m
the total displacement is
Δf = f (7) - f (0)
Δf = -46 - 3
Δf = - 49 m
the average speed is defined as the displacement between the time interval
v = Df / Dt
v = -49 / 7
v = - 7 m / s
B) the speed and acceleration of the end points of the motion
the speed of defined by
v = [tex]\frac{dx}{dt}[/tex]
in this case
v = [tex]\frac{df}{dt}[/tex]
v = -8t
let's calculate
v (7) = -8 7
v (7) = -56 m / s
acceleration is defined by
a = [tex]\frac{dv}{dt}[/tex]
a = - 8 m / s²
acceleration is constant throughout the movement
C) the point where the direction changes.
This point is a point where the position goes from positive to negative, the point f = 0
0 = -4t² +3
t = √¾
t = 0.866 s
On a level test track, a car with antilock brakes and 90% braking efficiency is determined to have a theoretical stopping distance (ignoring aerodynamic resistance) of 408 ft (after the brakes are applied) from 100 mi/h. The car is rear-wheel drive with a 110-inch wheelbase, weighs 3200 lb, and has a 50/50 weight distribution (front and back), a center of gravity that is 22 inches above the road surface, an engine that generates 300 ft-lb of torque, and overall gear reduction of 8.5 to 1 (in first gear), a wheel radius of 15 inches and a driveline efficiency of 95%. What is the maximum acceleration from the rest of this car on this test track
Answer:
a = 30.832 ft/s²
Explanation:
To solve this problem let's start by finding the braking acceleration using kinematics, where the distance is x = 408 ft, the initial velocity vo = 100 mi / h and the final velocity is zero v = 0
v² = v₀² - 2 a x
0 = v₀² - 2ax
a = [tex]\frac{v_o^2}{2x}[/tex]
Let's start by reducing the magnitudes to ft / s
v₀ = 100 mi / h (5280 foot / 1 mile) (1h / 3600 s) = 146.666 ft / s
let's calculate
a = [tex]\frac{146.66^2}{2 \ 408}[/tex]
a = 26.36 ft / s²
Let's call this acceleration a_effective, this acceleration is in the opposite direction to the speed of the vehicle.
Let's use a rule of three (direct proportions) to find the acceleration applied by the brake system (a1) which has an efficiency of 95%. or 0.95
a₁ = [tex]\frac{a_e}{0.95}[/tex]
Let's use another direct proportion rule If the acceleration of the brake system (a₁) for an applied acceleration (a) with an efficiency of 0.90
a = [tex]\frac{a_1}{0.90}[/tex]
we substitute
a = [tex]\frac{a_e}{0.95 \ 0.90}[/tex]
let's calculate
a = [tex]\frac{26.36}{ 0.95 \ 0.90}[/tex]
a = 30.832 ft/s²
This is the maximum relationship that the vehicle can have for when it brakes to stop at the given distance
If a 500-pound object is moved 200 feet how much work is being done?
a. 200 FT LB
b. 500 FT LB
c. 1000 FT LB
d. 100,000 FT LB
Answer:
D
Explanation:
Work = Distance x Mass
work done = 100,000 FT LB
What is work done ?
Work is done whenever a force moves something over a distance or The work done by a force is defined to be the product of component of the force in the direction of the displacement and the magnitude of this displacement.
Work done = force * displacement
given :
force = 500 pound
displacement = 200 feet
work done = 500 * 200 = 100,000 FT LB
correct option is d. 100,000 FT LB
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A car initially traveling at 15 m/s speeds up at a constant rate of 2.0 m/s2 for 3 seconds. The velocity of the car at the end of the 3 second interval is _________ m/s.
Answer:
Vf = 21 m/s
Explanation:
Data:
Initial Velocity (Vo) = 15 m/sAcceleration (a) = 2.0 m/s²Time (t) = 3 sFinal Velocity (Vf) = ?Use formula:
Vf = Vo + a * tReplace:
Vf = 15 m/s + 2.0 m/s² * 3sMultiply the acceleration with time:
Vf = 15 m/s + 6 m/sSolve the sum:
Vf = 21 m/sThe velocity of the car at the end of the 3 second interval is 21 meters per second.
A 4 m long metal bar tapped by a hammer on one end. A microphone recording the sound at the other end picks up two sound pulses; one which traveled through the metal bar and other which was traveling through room temperature air. These two pulses are separated by 11 msec. What is the speed of sound in the metal
Answer:
Explanation:
Speed of sound in air at room temperature = 346 m /s
Let speed of sound in metal given = v m /s
Time take by sound wave travelling through air = 4 / 346 = .01156 s
Time taken by sound wave travelling through metal = 4 / v s
Given ,
.01156 - 4 / v = 11 x 10⁻³ s = .011 s ( time taken by sound travelling in air is more )
4 /v = .01156 - .011 = .00056
v = 4 / .00056 = 7142.85 m /s
The kinetic theory states that the higher the temperature, the faster the
Answer: the higher the kinetic energy
Explanation:
Identify and sketch all the external forces acting on the chair. Because the chair can be represented as a point particle of mass m, draw the forces with their tails centered on the black dot in the middle of the chair. Be certain to draw your forces so that they have the correct orientation. Draw the vectors starting at the black dot. The location and orientation of the vectors will be graded. The length of the vectors will not be graded.
Answer:
y axis normal (N) and the weight (W)
x axis pplied force (F) and friction force (fr)
Explanation:
If we have a chair on a horizontal surface, the normal (N) and the weight (W) of the body act on the vertical axis.
On the x axis, the applied force (F) acts in the direction of movement and the friction force (fr) in the opposite direction of movement.
In this exercise we assume that the body tends to move to the right, all the forces can be seen in the adjoint
A wave in which the movement of the wave is perpendicular to the movement of the wave traveling through the medium-compression wave (longitudinal wave)
True or false?
Answer:
I'm rusty sorry if I'm wrong but true?
6th grade science I mark as brainliest !
Answer:
first is Atoms
4) is True
Two ropes are connected to a 200 kg dinghy. Two cousins each take one rope and pull. When the cousins pull in the same direction, the dinghy accelerates at a rate of 1.31 m/s2 to the east. If they pull in opposite directions, the dinghy has an acceleration of 0.526 m/s2 to the west. Assume the ropes are horizontal, and ignore any other horizontal forces acting on the dinghy. What is the magnitude of the force each cousin exerts on the dinghy
Answer:
The magnitude of the force each cousin exerts on the dinghy is 183.6 N and 78.4 N.
Explanation:
When the cousins pull in the same direction we have:
[tex] F_{1} + F_{2} = ma_{e} [/tex] (1)
Where:
F₁ and F₂ are the forces exerted by the two boys.
m: is the mass of the dinghy = 200 kg
[tex]a_{e}[/tex]: is the acceleration in the east direction
When the cousins pull in opposite directions we have:
[tex] F_{1} - F_{2} = ma_{w} [/tex] (2)
By adding equation (1) and (2):
[tex] 2F_{1} = m(a_{e} + a_{w}) [/tex]
[tex] F_{1} = \frac{200 kg(1.31 m/s^{2} + 0.526 m/s^{2})}{2} = 183.6 N [/tex]
Now, by entering F₁ into equation (1) we can find F₂:
[tex] F_{2} = ma_{e} - F_{1} = 200kg*1.31 m/s^{2} - 183.6 N = 78.4 N [/tex]
Therefore, the magnitude of the force each cousin exerts on the dinghy is 183.6 N and 78.4 N.
I hope it helps you!
Light-rail passenger trains that provide transportation within and between cities speed up and slow down with a nearly constant (and quite modest) acceleration. A train travels through a congested part of town at 4.0 m/s . Once free of this area, it speeds up to 11 m/s in 8.0 s. At the edge of town, the driver again accelerates, with the same acceleration, for another 16 s to reach a higher cruising speed. Part A What is the final speed
Answer:
25 m/s
Explanation:
Given that:
Initial speed, u = 4 m/s
Final velocity, V = 11 m/s
Time, t = 8 seconds
t2, = 16 seconds
Acceleration, a= (change in velocity) / time interval
a = (11 - 4) / 8
a = 7 / 8 = 0.875m/s²
Final velocity, v2 ;
Acceleration * t2
0.875 * 16 = 14
V2 = 14 m/s
Final speed : v + v2 = (11 + 14)m/s = 25m/s
Henrietta is going off to her physics class, jogging down the sidewalk at a speed of 4.15 m/sm/s. Her husband Bruce suddenly realizes that she left in such a hurry that she forgot her lunch of bagels, so he runs to the window of their apartment, which is a height 55.2 mm above the street level and directly above the sidewalk, to throw them to her. Bruce throws them horizontally at a time 5.50 ss after Henrietta has passed below the window, and she catches them on the run. You can ignore air resistance.
(a) With what initial speed must Bruce throw the bagels so that Henrietta can catch the bag just before it hits the ground?
(b) Where is Henrietta when she catches the bagels?
Answer:
Explanation:
Distance travelled by Henrietta in 5.5 s = 4.15 x 5.5 = 22.825 m .
Time taken by lunch of bagels to fall vertically by 55.2 m . Let it be t .
s = ut + 1/2 g t²
55.2 = 0 + .5 x 9.8 x t²
t² = 11.26
t = 3.356 s
By the time the lunch of bagels touches the hand of Henrietta , she would have travelled further by distance
s = 3.356 x 4.15 = 13.9 m
She is now at distance of 22.825 + 13.9 = 36.725 m from window .
So lunch of bagels must travel a horizontal distance of 36.725 m in 3.356 s which the time of fall of bagel .
Speed of bagel = distance / time
= 36.725 / 3.356
= 10.94 m /s
b )
Henrietta is 36.725 m from window at the time when she catches the bangel.
During a storm, a car traveling on a level horizontal road comes upon a bridge that has washed out. The driver must get to the other side, so he decides to try leaping the river with his car. The side of the road the car is on is18.0 m above the river, while the opposite side is only1.8 m above the river. The river itself is a raging torrent69.0 m wide.Part AHow fast should the car be traveling at the time it leaves the road in order just to clear the river and land safely on the opposite side?Part BWhat is the speed of the car just before it lands on the other side?
Answer:
Part A: The speed the car should be travelling when leaping the river is approximately 37.948 m/s
Part B: The speed of the car just before it lands is approximately 41.92345 m/s
Explanation:
The parameters of the car attempting leaping the river are;
The height of the car over the river = 18 m
The height of the opposite side of the bridge above the river = 1.8 m
The width of the river, x = 69.0 m
Part A
The time, 't' it would take the car to fall from 18 m above the river to 1.8 m above the river is given as follows;
t = √(2·h/g)
Where;
h = The height of the fall = 18 m - 1.8 m = 16.2 m
g = The acceleration due to gravity = 9.8 m/s²
∴ t = √(2×16.2 m/(9.8 m/s²)) = (9/7)·√2 s
The horizontal speed, 'vₓ', with which the car should be travelling at the time it leaves the road in order just to clear the river and land safely on the opposite side is given as follows;
vₓ = x/t = 69.0 m/((9/7)·√2 s) = (161/6)·√2 m/s ≈ 37.948 m/s
The horizontal speed the car should be travelling when leaping the river, vₓ ≈ 37.948 m/s
Part B;
The vertical velocity of the car is given as follows;
[tex]v_y[/tex]² = [tex]u_y[/tex]² + 2·g·h
∴ [tex]v_y[/tex]² =2·g·h = 2 × 9.8 m/s² × 16.200 m = 317.52m²/s²
[tex]v_y[/tex] = √(317.52 m²/s²) = (63/5)·√2 ≈ 17.819 m/s
The magnitude of the speed of the car, 'v', just before it lands is given using Pythagoras' theorem for resultant vectors as follows;
v = √([tex]v_y[/tex]² + vₓ²) = √(317.52 m²/s² +((161/6)·√2 m/s)²) ≈ 41.92345 m/s
The speed of the car just before it lands, v ≈ 41.92345 m/s.
A wall clock has a minute hand with a length of 0.46 m and an hour hand with a length of 0.24 m. Take the center of the clock as the origin, and use a Cartesian coordinate system with the positive x axis pointing to 3 o'clock and the positive y axis pointing to 12 o'clock. Write the vector that describes the displacement of a fly if it quickly goes from the tip of the minute hand to the tip of the hour hand at 3:00 P.M. (Let vector D represents the displacement of the fly.)
Answer:
the vector that describes the displacement of a fly if it quickly goes from the tip of the minute hand to the tip of the hour hand at 3:00 P.M is ; { 0.24 m(i) - 0.46 m(j) }
Explanation:
Given the data in the question;
as illustrated in the image below,
3:00 pm means
the hour hand is on 3 i.e along x-axis
while the minute hand is on 12 i.e along y-axis
so Displacement will be;
D = ( 0.24 + 0i) - ( 0 + 0.46j )
D = { 0.24 m(i) - 0.46 m(j) }
Therefore, the vector that describes the displacement of a fly if it quickly goes from the tip of the minute hand to the tip of the hour hand at 3:00 P.M is ; { 0.24 m(i) - 0.46 m(j) }
50 points Two waves combine with constructive interference. What must be true of the
combined wave that forms?
A. It has a lower frequency than that of the original waves.
B. It has a higher amplitude than that of the original waves.
C. It has a higher frequency than that of the original waves.
D. It has a lower amplitude than that of the original waves.
Answer:
it has a higher amplitude than that of the original waves
Explanation:
trust me its right
The two waves combined with constructive interference have a higher amplitude than the original wave.
Which wave has the highest amplitude?High energy waves are characterized by high amplitude. Low energy waves are characterized by their small amplitude. As explained in Lesson 2, wave amplitude is the maximum amount of particle movement on a medium from a resting position.
What are superposition and interference?Superposition is a combination of two waves in the same place. Constructive interference occurs when two identical waves interfere in phase. Destructive interference occurs when two identical waves are exactly out of phase and overlap.
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You are inside the Great Hall, 15 m from the north wall with the doors to the RMC, and centered between two open doors that are 3 m apart. Someone is blairing a 200 Hz tone outside the Great Hall so that it enters the doors as a plane wave. You hear a maximum intensity in your current position. As you walk along the direction of the wall with the doors (but maintain a distance 15 m from the wall), how far will you walk (in m) to hear a minimum in the sound intensity
Answer:
Δr = 0.425 m
Explanation:
This is a sound interference exercise, the expression for destructive interference is
Δr = (2n + 1) λ / 2
in this case the movement is in the same direction as the sound, therefore the movement is one-dimensional
let's use the relationship between the speed of sound and its frequency and wavelength
v = λ f
λ = v / f
the first minium occurs for n = 0
Δr = λ / 2
Δr = v / 2f
Δr = [tex]\frac{340}{2 \ 400}[/tex]
Δr = 0.425 m
this is the distance from the current position that we assume in the center of the room
Determine one way you can contribute to water in the atmosphere in your day-to-day activities pleaseeeee helppp
Answer:
agricultural production of food
Explanation:
Match the measurements with the proper SI unit.
Acceleration:
A. Meters
B. Meters per second
C. Meters per second squared
Velocity:
A. Meters
B. Meters per second
C. Meters per second squared
Distance:
A. Meters
B. Meters per second
C. Meters per second squared
Explanation:
C. meter per second squared
B. meter per second
A. meter
Answer:
b. meters per second
c.meters per second squared
c.meters
Explanation:
ginawa ko na rin KC toh
A fan is set on a desk next to a stack of paper. The fan is turned on and then turned
on HIGH SPEED. Which of the following would best apply Newton's First Law to this
example.
The papers accelerated due to the force of the fan.
The papers are acted upon by an unbalanced force from the fan.
O The papers exerted an equal force on the air blown by the fan.
O The papers that were the heaviest were blown the closest.
Answer:
The second option - the papers are acted upon by an unbalanced force from the fan.
Explanation:
In the 1986 Olympic Games, Abdon Pamich of Italy won the 50 km walk, in
4h, 11 min and 11.2 s. Find his average speed in m/s.
Answer: 4
Explanation: because my pet monkey said it was
Surface Features on earth combine to form the(blank) or area ,Will mark brainliest if someone give’s me the word that fit’s in there.
A lunar eclipse occurs when the Moon passes through Earth's
A plane wishes to fly due north to an airport which is 205 km away. The plane can fly at a speed in still air of 220 km/h. A wind of 43 km/h blows from east to west.
a. In which direction,relative to north, should the plane head to reach it’s destination?
b. How long does this take?
Answer:
nique ta mama
Explanation:
A motorcycle reaches the speed of 40 m / s, how far does it travel in 10 seconds?
Answer:
d = 200 m
Explanation:
Data:
Initial Velocity (Vo) = 0 m/s Final Velocity (Vf) = 40 m/s Time (t) = 10 s Distance (d) = ?Use formula:
[tex]\boxed{d=\frac{Vf+Vo}{2}*t}[/tex]Replace:
[tex]\boxed{d=\frac{40\frac{m}{s}+0\frac{m}{s}}{2}*10s}[/tex]Sum in the numerator:
[tex]\boxed{d=\frac{40\frac{m}{s}}{2}*10s}[/tex]It divides:
[tex]\boxed{d=20\frac{m}{s}*10s}[/tex]Simplify the seconds (s), and multiply:
[tex]\boxed{d=200\ m}[/tex]How far does it go?
Travel a distance of 200 meters.
3. What were some of the materials use in ancient history times in the
making of the ball?
Answer: Fur stuffed with feathers.
Explanation:
Ball games were popular throughout ancient history but also in the Middle Ages. Many of these games are the forerunners of today's American football and soccer. There are data on almost all continents on how peoples practiced some ball sports in antiquity. The game balls' look was not like today, it was mostly egg-shaped, and the materials for making it were different. The most common material for making the ball was leather, which was filled with feathers.
What is the momentum of a 0.000015 kg mosquito flying straight at you with a velocity of 5.20 m/s?
Answer:
Momentum, [tex]p=7.8\times 10^{-5}\ N-m[/tex]
Explanation:
Given that,
Mass of a mosquito, m = 0.000015 kg
Velocity of the mosquito, v = 5.2 m/s
We need to find the momentum of the mosquito. The momentum of an object is given by :
p = mv
Put all the values in the above formula.
[tex]p=0.000015\ kg\times 5.2\ m/s\\\\p=0.000078\ N-m\\\\\text{or}\\\\p=7.8\times 10^{-5}\ N-m[/tex]
So, the momentum of the mosquito is [tex]7.8\times 10^{-5}\ N-m[/tex].
Iron has a specific heat of o.45 J/g °C. Removing -1.16 E 2 J of energy lowered the temperature of iron from 89 °C to 26.41 °C. What was the mass of the iron?
Answer:
m = 4.11 grams
Explanation:
Given that,
The specific heat of Iron, c = 0.45 J/g°C
Heat removed, [tex]Q=1.16\times 10^2\ J[/tex]
Initial temperature, [tex]T_i=89^{\circ} C[/tex]
Final temperature, [tex]T_f=26.41^{\circ} C[/tex]
We need to find the mass of the iron. We know that the heat removed in terms of specific heat is given by :
[tex]Q=mc\Delta T\\\\m=\dfrac{Q}{c\Delta T}\\\\m=\dfrac{-1.16\times 10^2}{0.45\times (26.41-89)}\\\\m=4.11\ g[/tex]
So, the mass of the iron is 4.11 grams.
WILL GIVE BRAINLIEST!!
What is a way to transfer charge in which an object becomes polarized?
Answer:
I answered Number 4 (Solids and Elasticity)
Explanation:
solids and elasticity
The height (in centimeters) at time t (in seconds) of a small mass oscillating at the end of a spring is h(t)=5sin(2πt). Estimate its instantaneous velocity at t=3
Answer:
h (3) = 0
Explanation:
In this exercise they give us the expression that governs the movement
h (t) = 5 sin (2πt)
remember that the angles are in radians.
To calculate the instantaneous velocity we substitute
h (3) = 5 sin (2π 3)
h (3) = 0
therefore the body this is its position of equilibrium
What is the symbol for carbonate ?
Identify the independent variable(s) in Asch's original experiment.
Answer:
How do I answer this I don't understand the question
Explanation:
