A car goes from 80 kn/h to 20 km/h in 0.5 h. What is the acceleration in km/h^2? *
Answer:
In physics, acceleration is defined as the rate of change of the velocity of an object with respect to time. That is A = VF - VI /T; Where A = Acceleration VF = Final velocity = 20 km VI = Initial velocity = 80 km T= Time = 0.5 hr A = (20 - 80)/ 0.5 = - 60/.5 A = - 120 Km/ hr^2 Therefore, the acceleration of the car is -120 km/hr^2. Because the value is negative, the appropriate name that describe it is deceleration.I Hope this helps
Mishael walks 30 meters East, turns around and walks 25 meters West, then turns again and walks 50 meters East. What is his displacement? Group of answer choices 5 meters East 105 meters East 5 meters West 55 meters East
Answer:
55 meters East
Explanation:
if you start at the origin, "add" 30 meters (going east #1), subtract 25 meters (going west #1), then add 50 meters (going east #2), you should get 55 meters East.
Hope this helps!
Read the following scenario and decide if it is a hypothesis, theory or law.
Sue is camping and decides to drop a rock off a cliff. She finds a small rock, drops it.
and notes that it takes approximately two seconds to land. She then finds a somewhat
larger rock and concludes that the bigger rock should take less than two seconds to
land because it is bigger.
Answer:
Law
Explanation:
This is newton's second law of motion.
The Problems: 1. Xavier starts at a position of 0 m and moves with an average speed of 0.50 m/s for 3.0 seconds. He normally moves faster than this but he'd just woken up. Determine his final position. 2. A hedgehog starts at a position of 0 m and moves with an average speed of 0.75 m/s for 4.0 s. Determine the final position of the hedgehog. 3. A tortoise starts at a position of 1.0 m and moves with an average speed of 1.25 m/s for 3.0 s, what is the final position of the tortoise? Cintia, in a 100 m race, has an average speed of 1.25 m/s. What was her race time? 5. Angel runs a marathon with an average speed of 5 miles/hour. How long did it take to finish?
Answer:
(1). His final position is 1.5 m.
(2). The final position of the hedgehog is 3 m.
(3). The final position of the tortoise
(4). Her race time is 80 sec.
(5). It take to finish in 5 hr.
Explanation:
(1). Given that,
Initial position = 0 m
Average speed = 0.50 m/s
Time = 3.0 s
We need to calculate the final position
Using formula of average speed
[tex]v_{av}=\dfrac{x_{f}+x_{i}}{t}[/tex]
Where, [tex]x_{f}[/tex] = final position
[tex]x_{i}[/tex] = Initial position
t = total time
Put the value into the formula
[tex]0.50=\dfrac{x_{f}+0}{3.0}[/tex]
[tex]x_{f}=0.50\times3.0[/tex]
[tex]x_{f}=1.5\ m[/tex]
(2). Given that,
Initial position = 0 m
Average speed = 0.75 m/s
Time = 4.0 s
We need to calculate the final position
Using formula of average speed
[tex]v_{av}=\dfrac{x_{f}+x_{i}}{t}[/tex]
Put the value into the formula
[tex]0.75=\dfrac{x_{f}+0}{4.0}[/tex]
[tex]x_{f}=0.75\times4.0[/tex]
[tex]x_{f}=3\ m[/tex]
(3). Given that,
Average speed = 1.25 m/s
Time = 3.0 sec
Initial position = 1.0 m
We need to calculate the final position
Using formula of average speed
[tex]v=\dfrac{x_{f}+x_{i}}{t}[/tex]
Put the value into the formula
[tex]1.25=\dfrac{x_{f}+1.0}{3.0}[/tex]
[tex]x_{f}=1.25\times3.0-1.0[/tex]
[tex]x_{f}=2.75\ m[/tex]
(4). Given that,
Average speed = 1.25 m/s
Distance = 100 m
We need to calculate the time
Using formula of time
[tex]t=\dfrac{d}{v}[/tex]
Put the value into the formula
[tex]t=\dfrac{100}{1.25}[/tex]
[tex]t=80 sec[/tex]
(5). Given that,
Average speed = 5 miles/hr
Suppose, distance = 25 miles
We need to calculate the time
Using formula of time
[tex]t=\dfrac{d}{v}[/tex]
Put the value into the formula
[tex]t=\dfrac{25}{5}[/tex]
[tex]t=5\ hr[/tex]
Hence, (1). His final position is 1.5 m.
(2). The final position of the hedgehog is 3 m.
(3). The final position of the tortoise
(4). Her race time is 80 sec.
(5). It take to finish in 5 hr.
What is the acceleration of the object at t = 4s?
Answer:
no answer of this bcuz to find aclleration.initial velocity and final velocity too... I think question is wrong
The higher the altitude then _________ the air pressure... *
lower
higher
hotter
colder
[tex]\mathfrak{\huge{\pink{\underline{\underline{AnSwEr:-}}}}}[/tex]
Actually Welcome to the Concept of the Physics,
Since we know that, earth is surrounded by a atmosphere, hence on the surface we have high air density but at a higher altitude there is less air, thus pressure of air also less,
The higher the Altitude then lower the air pressure..
14. Which of the following denotes impedance?
A. H
B. R
C. Z
D. XL
The diagram shows a ball resting at the top of a hill.
Which statement best describes the energy in this
system?
Х
O The potential energy in the system is greatest at X.
O The kinetic energy in the system is greatest at X.
O Total energy in the system decreases as the ball
moyes from X to Y.
O Tofd energy in the system increases as the ball
moves from X to Y.
Y
Answer:
the answer is A The potential energy in the system is greatest at X.
Explanation:
i know things
An airplane is flying at a velocity of 79 m/s eastward relative to the air. Due to a high-pressure region to the north, the velocity of the air relative to the ground is 18 m/s southward. Find the ground speed of the airplane.
_________ m/s
Answer:
81.02m/s toward the southeast
Explanation:
use Pythagorean theorem
c^2=a^2+b^2
create a coordinate system, 79m/s toward the east and 18m/s toward the south.
root(79^2+18^2)=81.02
The surface of an insulating sphere (A) is charged up uniformly with positive charge, and brought very close to an identical–size conducting sphere (B) that has no net charge on it. The spheres do not make contact.
A) Sketch the distribution of charge on each sphere.
B) Will the spheres attract, repel, or not interact with each other? Explain.
C) When the spheres make contact, they repel each other. Explain this behavior.
Answer:
A) A negative charge of value Q is induced on sphere B
B) there is an attraction between sphere
C) The charge of sphere A is distributed between the two spheres,
Explanation:
This is an electrostatic problem, in general charges of the same sign attract and repel each other.
with this principle let's analyze the different situations
A) The sphere A that is insulating has a charge on its surface and zero charge is its interior
The conducting sphere B has zero charge, but the sphere A creates an attraction in the electrons, therefore a negative charge of the same value as the charge of the sphere A is induced in the part closest and in the part farther away than one that a positive charge.
A negative charge of value Q is induced on sphere B
B) In this case there is an attraction between sphere A with positive charge and sphere B with negative induced charge
C) When the two spheres come into contact, the charge of sphere A is distributed between the two spheres, therefore each one has a positive charge of value half of the initial charge, as now we have net positive charges in the two spheres charges of the same sign repel each other so the spheres separate
how does radiant energy transfer energy?
Answer:
Radiant energy, energy that is transferred by electromagnetic radiation, such as light, X-rays, gamma rays, and thermal radiation, which may be described in terms of either discrete packets of energy, called photons, or continuous electromagnetic waves.
Explanation:
Students are studying the two-dimensional motion of objects as they move through the air. Specifically, they are examining the behavior of a sphere that is launched horizontally from a location above the floor with an initial velocity vo in the +3 direction, as shown in the figure. The students assume that the positive directions are along the sphere's initial velocity for horizontal motion and downward for vertical motion.
The horizontal displacement of the object from its starting point is x, and the vertical displacement of the object from its starting point is y. One of the students derives an equation for y in terms of xx and other quantities. After examining the equation, the student claims that y is proportional to x^2.
Required:
Derive an equation for the vertical coordinate y of the sphere as a function of x, v0, and physical constants, as appropriate.
Answer:
y = - (½ g / v₀²) x²
Explanation:
This is a projectile launch exercise where there is no acceleration on the x-axis so
x = v₀ₓ t
v₀ₓ = v₀ cos tea
y = [tex]v_{oy}[/tex] t - ½ g t2
v_{oy} = v₀ sin θ
as the sphere is thrown horizontally, the angle is tea = 0º, so the initial velocity remains
v₀ₓ = v₀
v_{oy} = 0
we substitute in our equations
x = v₀ t
y = - ½ g t²
we eliminate the time from these equations, we substitute the first in the second
y = - ½ g (x / v₀)²
y = - (½ g / v₀²) x²
this is the equation of a parabola
A penguin is trying to cross the street. It’s velocity v as a function of time t is given in the graph below where rightwards is the positive velocity given. At what time does the penguib have the same positition as t = 0s?
Answer:
3.5
Explanation:
Khan Academy gives the answer here.
PLEASE HELP!!
A football kicker lines up to kick a game winning kick. The goalpost is 30m away and the ball must clear the
3.3m high cross-bar. If the kick leaves his foot at an angle of 35 degrees, how fast must the kick be to be
good (assuming no one blocks it)?
Answer:
19.26 m/s
Explanation:
I will put a photo
2. Who bombarded molybdenum with atomic number (Z=42) with fast moving
neutrons?
Answer:
This question appears incomplete
Explanation:
This question appears incomplete, however Molybdenum-99 (⁹⁹Mo) is produced by bombarding Molybdenum-98 (⁹⁸Mo) with fast moving neutrons (¹₀n) as shown below
⁹⁸₄₂Mo + ¹₀n ⇒ ⁹⁹₄₂Mo + ⁰₀γ
This reaction is a nuclear caption reaction (which occurs in a nuclear reactor) for the production of Molybdenum-99 (⁹⁹Mo) which serves as a "precursor" for the production of medically viable/ Clinical Grade Technutium-99m (⁹⁹Tc) through Ion-exchange technique.
Because of your knowledge of physics, you have been hired as a consultant for a new James Bond movie, "Oldfinger". In one scene, Bond jumps horizontally off the top of a cliff to escape a villain. To make the stunt more dramatic, the cliff has a horizontal ledge a distance h beneath the top of the cliff which extends a distance LL from the vertical face of the cliff. The stunt coordinator wants you to determine the minimum horizontal speed, in terms of L and h, with which Bond must jump so that he misses the ledge.
Answer:
v = [√(g/2h)]L
Explanation:
Let v be the initial horizontal velocity, t be the time James Bond uses to jump over the ledge of length, L.
So, vt = L and t = L/v
Also, since James Bond has no initial horizontal velocity, he falls freely through the distance, h so we use the equation y - y' = ut - 1/2gt², where y = 0 (at the top of the cliff) and y' = -h, u = 0 (initial vertical velocity), g = acceleration due to gravity = 9.8 m/s² and t = the time it takes to jump off the cliff = L/v.
Substituting these values into the equation, we have
y' - y = ut - 1/2gt²
-h - 0 = 0 × t - 1/2g(L/v)²
-h = - 1/2gL²/v²
v² = gL²/2h
taking square root of both sides, we have
v = [√(g/2h)]L
So, James Bond's minimum horizontal speed is v = [√(g/2h)]L
Which state is made up of separated electrons and positive ions?
Answer: Plasma
Explanation: It's particles are ionized and just took quiz
Answer:
plasma
Explanation:
A football player kicks a ball with an initial velocity of 30 meters per second at an angle of 53° above the horizontal. how long will the ball be in the air for
At time t, the ball attains a height y of
y = (30 m/s) sin(53º) t - 1/2 g t²
where g = 9.80 m/s² is the magnitude of the acceleration due to gravity.
Solve for t when y = 0:
(30 m/s) sin(53º) t - 1/2 g t² = 0
t ((30 m/s) sin(53º) - (4.90 m/s²) t ) = 0
t = 0 or (30 m/s) sin(53º) - (4.90 m/s²) t = 0
We ignore the first solution, since that refers to the moment the ball is kicked.
(30 m/s) sin(53º) - (4.90 m/s²) t = 0
(30 m/s) sin(53º) = (4.90 m/s²) t
t = (30 m/s) sin(53º) / (4.90 m/s²)
t ≈ 4.9 s
Given the vector A with components Ax = 2.00, Ay = 6.00, the vector B with components Bx = 2.00, By = 22.00, and the vector D = A - B, calculate the magnitude and angel with the x axis of the vector D
Answer:
The magnitude of vector d is 16 and the angle with the x-axis is 270°
Explanation:
Operations With Vectors
Given two vectors in rectangular components:
[tex]\vec a=(ax,ay)\ ,\ \vec b=(bx,by)[/tex]
The sum of the vectors is:
[tex]\vec a+\vec b=(ax+bx,ay+by)[/tex]
The difference between the vectors is:
[tex]\vec a-\vec b=(ax-bx,ay-by)[/tex]
The magnitude of [tex]\vec a[/tex] is:
[tex]|\vec a|=\sqrt{ax^2+ay^2}[/tex]
The angle [tex]\vec a[/tex] makes with the horizontal positive direction is:
[tex]\displaystyle \tan\theta=\frac{ay}{ax}\\[/tex]
The question provides the vectors:
[tex]\vec a=(2,6)[/tex]
[tex]\vec b=(2,22)[/tex]
[tex]\vec d=\vec a-\vec b[/tex]
Calculate:
[tex]\vec d=(2,6)-(2,22)=(0,-16)[/tex]
The magnitude of [tex]\vec d[/tex] is:
[tex]|\vec d|=\sqrt{0^2+(-16)^2}=\sqrt{0+256}=16[/tex]
The angle is calculated by:
[tex]\displaystyle \tan\theta=\frac{-16}{0}[/tex]
The division cannot be calculated because the denominator is zero. We need to estimate the correct angle by looking at the components of the vector. Since the x-coordinate is zero and the y-coordinate is negative, the vector points downwards (south), thus the angle must be -90° or 270° if the range goes from 0° to 360°.
The magnitude of vector d is 16 and the angle with the x-axis is 270°
Bill drives and sees a red light. He slows down to a stop. A graph of his velocity over time is shown below.
What is his average acceleration from 0 to 10 seconds?
Answer: its actually 0
Explanation: i read the khan academy hints and the answer is 0
yes the answer is 0 and if its not and have this graph its -2.0
Different colors of light are associated with different wavelengths.
Answer:
yepp
Explanation:
you sure is right
A ball is dropped from the top of a building and hits the street below in 4.25 s. How tall is the building? Show work for brainliest.
Answer:
90.3125 m
Explanation:
[tex]s = ut + \frac{1}{2} a {t}^{2} [/tex]
a = 10m/s^2 (constant)
S=height
U=initial velocity
a= gravitational acceleration
t= time
s = 0 + 1/2 * 10 * 4.25 ^2
u is 0 because it is dropped without velocity
s =90.3125 m
4. Two identical charges are 25cm apart. They repel each other with the force of 2 x 10-6 Find Each
charge?
Answer:
Both charges are of the same sign (positive or negative) and with a value of 3.73 ηc.
Explanation:
Coulomb's Law
The electrical force between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between the two objects.
Written as a formula:
[tex]\displaystyle F=k\frac{q_1q_2}{d^2}[/tex]
Where:
[tex]k=9\cdot 10^9\ N.m^2/c^2[/tex]
q1, q2 = the objects' charge
d= The distance between the objects
We know both charges are identical, i.e. q1=q2=q. Since the force is repulsive, both charges are positive or negative.
We also are given the force between them:
[tex]F=2\cdot 10^{-6}\ N[/tex]
And also the distance
d=25 cm = 0.25 m
Substituting all into the formula:
[tex]\displaystyle 2\cdot 10^{-6}=9\cdot 10^9\frac{q.q}{0.25^2}[/tex]
The product of [tex]q.q=q^2[/tex]. Operating:
[tex]\displaystyle 2\cdot 10^{-6}=9\cdot 10^9\frac{q^2}{0.0625}[/tex]
Operating:
[tex]\displaystyle 0.0625\cdot 2\cdot 10^{-6}=9\cdot 10^9\cdot q^2[/tex]
Solving for q:
[tex]\displaystyle q^2=\frac{0.0625\cdot 2\cdot 10^{-6}}{9\cdot 10^9}[/tex]
[tex]q^2=1.39\cdot 10^{-17}[/tex]
[tex]q=\sqrt{1.39\cdot 10^{-17}}=3.73\cdot 10^{-9}\ c= 3.73\ \eta c[/tex]
Both charges are of the same sign (positive or negative) and with a value of 3.73 ηc.
A cars momentum is p when it’s traveling with a velocity of v. If the velocity of that car doubles, what is the new momentum of the car
Answer:
2p
Explanation:
I just did it
Answer:
2p
Explanation: just did it in Edgen
A stone is thrown straight up at an upward speed of 8.0 m/s from the top of the cliff. The stone hits the ground and stops 5.0 s later. What is the height of the cliff?
Answer:
22
Explanation:
While making some observations at the top of the 63 m tall Astronomy tower, Ron
accidently knocks a 0.5 kg stone over the edge. How fast will the stone be moving when
it hits the ground?
Analysing the Question:
We are given:
height of the tower (h) = 63 m
mass of stone (m) = 0.5 kg
initial vertical velocity of the stone (u) = 0 m/s [ since the stone fell, there was no force applied on it to go downwards]
final vertical velocity of the stone (v) = v m/s
acceleration of the stone due to gravity (a) = 10 m/s² [we are letting g = 10]
** We will be neglecting air resistance in this answer**
Finding the final velocity of the stone:
from the third equation of motion
v² - u² = 2ah
replacing the variables
v² - (0)² = 2(10)(63)
v² = 1260
v = √1260
v = 35.5 m/s
Moments later, your friend passes the ball back up to you. Your friend throws it straight
upwards at a speed of 16.6 m/s. If you catch it when it is still travelling upward at 5.3
m/s how far apart are you and your friend?
Analysing the question:
since the ball is thrown upwards, the gravity will be applied opposite to the motion of the ball
We are given:
acceleration due to gravity (a) = -10 m/s²
initial upward velocity (u) = 16.6 m/s
final upward velocity (v) = 5.3 m/s
distance between the friends (s) = s m
Neglecting air resistance
Solving for the distance between the friends:
from the first equation of motion
v = u + at
replacing the variables
5.3 = 16.6 + (-10)(t)
-10(t) = 5.2 - 16.6
-10 (t) = -11.3
t = 1.13 seconds
from the second equation of motion
s = ut + 1/2 at²
replacing the variables
s = (16.6)(1.13) + -5(1.13)²
s = 18.8 - 6.4
s = 12.4 m
Therefore, the 2 friends are 12.4 m apart
16. How much does the gravitational potential
energy of a 1.2 kg textbook increase if you lift it
upward 32 cm?
Answer:
El uso mas común de la energía potencial gravitacional, se da en los objetos cercanos a la superficie de la Tierra donde la aceleración gravitacional, se puede presumir que es constante y vale alrededor de 9.8 m/s2.
Explanation:
What is the formula for the compound formed between Na and Se?
Answer:
gold
Explanation:
How could you increase electric force using each factor
Increasing the separation distance between objects decreases the force of attraction or repulsion between the objects. And decreasing the separation distance between objects increases the force of attraction or repulsion between the objects. Electrical forces are extremely sensitive to distance.
The increment of the electric force by each factor should be explained below.
What is electric force?An electric force refers to the interaction of the attractive force or the repulsive force that lies between two charged bodies. In the case when there should be increment in the separation distance that lies between the objects so it reduced the attraction force. Due to the reduction in the seperate distance there should be an increment in the attraction force. Also, the electric force should be very sensitive with respect to the distance.
Learn more about electric force here: https://brainly.com/question/17562167