Answer:
a) the cheetah's top speed is 64.4 miles/hr
b) time taken to reach top speed is 3.3 seconds
Explanation:
Given the data in the question;
Cheetahs can accelerate to a speed of 21.8 m/s in 2.50 s.
They can continue to accelerate to reach a top speed of 28.8 m/s.
a) Express the cheetah's top speed in mi/h. (Express your answer to three significant figures.)
The cheetah's top speed = 28.8 m/s = ( 28.8 × 2.237 ) miles/hr
= 64.4256 ≈ 64.4 miles/hr
Therefore, the cheetah's top speed is 64.4 miles/hr
b) Starting from a crouched position, how long does it take a cheetah to reach its top speed.
given that
v₁ = 21.8 m/s and t₁ = 2.50 s
let a represent the acceleration of the cheetah
From the First Equation of Motion;:
v = u + at
we substitute
21.8 = 0 + ( a × 2.50 )
21.8 = a × 2.50
a = 21.8 / 2.50
a = 8.72 m/s²
Now, let the time taken by cheetah to reach top speed ( 28.8 m/s ) be t
so from the first equation of motion;
v = u + at
we substitute
28.8 = 0 + ( 8.72 × t )
t = 28.8 / 8.72
t = 3.3 seconds
Therefore, time taken to reach top speed is 3.3 seconds
What is the acceleration of a 0.30 kilogram ball that is hit
with a force of 27 N?
Answer: 90
Explanation: a=Fnet/M
=27/0.30
=90
the acceleration is 90
Answer:
The acceleration of the ball is 83.333ms2 [forward].
Explanation:
i hope it helps :)
While taking a psychology exam, Lori got up and shut the classroom door due to outside noise that affected her concentration. Which theory explains Lori’s behavior?
Group of answer choices
Drive-reduction theory
Expectancy theory
Instinct theory
Arousal theory
Answer:
drive reduction theory
Explanation:
I would say that because of all the cars beeping and making A Lot of cachos on the street so that will definitely affect her taking her exam
Theory explains Lori’s behavior is b) Drive-reduction theory
What is Drive-reduction theory?
It is based on the idea that the primary motivation behind all human behavior is to reduce drives . A drive is a state of discomfort which is triggered by a person's physiology or biological need .
so , she removed discomfort that can happen by the noise outside the classroom in order to maintain student's concentration
correct answer is b) Drive-reduction theory
learn more about Drive-reduction theory
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HELP PLSS I CANT FAIL!!!
Elements from Period 3 of the periodic table are highlighted. Which element
is a metalloid?
A. Sodium
B. Argon
C. Sulfur
D. Silicon
What is the Y-component of a vector A, which is of magnitude
16-12 and at a 45° angle to the horizontal?
Explanation:
the answer is in the image above
The Y-component of a vector A, which is of magnitude 16√2 and at a 45° angle to the horizontal would be 16
What is a vector quantity?The quantities that contain the magnitude of the quantities along with the direction are known as the vector quantities.
Examples of vector quantities are displacement, velocity acceleration, force, etc.
As given in the problem we have to find out the Y-component of a vector A, which is of magnitude 16√12 and at a 45° angle to the horizontal,
Y component of the vector A = 16√2 sin45°
=16√2 ×1/√2
=16
Thus, the Y component of vector A would be 16.
To learn more about the vector quantity here, refer to the link;
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Each tire on a car has a radius of 0.330 m and is rotating with an angular speed of 13.9 revolutions/s. Find the linear speed v of the car, assuming that the tires are not slipping against the ground.
Answer:
the linear speed of the car is 28.83 m/s
Explanation:
Given;
radius of the car, r = 0.33 m
angular speed of each tire, ω = 13.9 rev/s = 13.9 x 2π = 87.35 rad/s
The linear speed of the car is calculated as;
V = ωr
V = 87.35 rad/s x 0.33 m
V = 28.83 m/s
Therefore, the linear speed of the car is 28.83 m/s
What is the resistance of a bulb of 4ow
connected in a line of 220v?
2
Answer:
1210 ohm
Explanation:
Given :
P=40 W
V=220 V
Now,
[tex]P=\frac{V^{2} }{R} \\40=\frac{(220)^{2} }{R} \\40R=48400\\R=\frac{48400}{40} \\R=1210 ohm[/tex]
Therefore, resistance of bulb will be 1210 ohm
Can someone please help me with this problem
Answer:
resultant is equal to the sum of A vector or B vector and draw resultant in order that the tail of resultant vector concides with tail of vector a and head of resultant concides with the head of vector b
Explanation:
which statement summarized the difference between mass and weight?
Answer:
The second statement.
A 10,000J battery is depleted in 2h. What power consumption is this? *
A) 5000W
B) 3W
C) 1.4W
D) 20000W
show your work please
Answer:
C) 1.4W
Explanation:
Given;
energy of the battery, E = 10,000 J
duration of the battery, t = 2 hours
The power consumption of the battery is calculated as;
[tex]Power = \frac{Energy}{time} \\\\Power = \frac{10,000}{2 \times 3600 } \\\\Power = 1.4 \ J/s = 1.4 \ W[/tex]
Therefore, the power consumption of the battery is 1.4 W
in physics If we interchange rows and columns of Matrix A, what is the new matrix known as 'Matrix' A ?
Answer:
The correct answer is (C), as explained below. The transpose of a matrix is created by interchanging corresponding rows and columns.
Switching Rows
You can switch the rows of a matrix to get a new matrix.
Explanation:
If A is an m × n matrix and AT is its transpose, then the result of matrix multiplication with these two matrices gives two square matrices: A AT is m × m and AT A is n × n. ... Indeed, the matrix product A AT has entries that are the inner product of a row of A with a column of AT.
Prepare a stock available at home following the procedure you learned in this lesson. Have a picture of the finished product and a narration on how you do it
Answer:
NO, 1. is stocks
2. is also stocks
bouquit GARNI IS NUMBER 3
NUMBER 4 IS ACID PRODUCTS
number 5 is brown stock
Explanation:
stocks are bones
When rebuilding her car's engine, a physics major must exert 405 N of force to insert a dry steel piston into a steel cylinder. What is the magnitude of the normal force in newtons between the piston and cylinder
Answer:
[tex]N=675N[/tex]
Explanation:
From the question we are told that:
Force [tex]F=405N[/tex]
Generally the equation for Normal force in this case is is mathematically given by
[tex]F=\mu_s N[/tex]
Where
Static Friction=[tex]\mu_s[/tex]
[tex]\mu_s=0.6[/tex]
Therefore
[tex]N=\frac{F}{\mu_s}[/tex]
[tex]N=\frac{405}{0.6}[/tex]
[tex]N=675N[/tex]
What will be resultant force ?
Answer:
It will go to the right way 500N.
Explanation:
Because, up and down is 300 and 300 so it minus each other and get zero, that made the resultant force will never go up or down. And now we are focusing on the left and right. 900 is more than 400, so it will go to the right. But we also pull to the left too!! That make the resultant force is 500 to the right.
A 3.0 kg pendulum swings from point A of height ya = 0.04 m to point B of height yb = 0.12 m, as seen in the diagram below.
Answer:
3.0−0.12=2.88 or 2.88÷0.04=72
0.04×3.0=0.12 and 0.04+3.0=3.04
Answer: 2.4 J
Explanation: Khan Academy
HELP ME PLS
Chlorine (chemical symbol Cl) is located in Group 17, Period 3. Which is
chlorine most likely to be?
A. A metalloid with properties of both metals and nonmetals
B. A gaseous, highly reactive nonmetal
C. A soft, shiny, highly reactive nonmetal
D. A soft, shiny, highly reactive metal
Answer:
Option B
Explanation:
A gaseous, highly reactive non-metal
Answer:B
Explanation:I just took the test
explanation on energy from air pressure light from water pressure
Hank and Harry are two ice skaters whiling away time by playing 'tug of war' between practice sessions. They hold on to opposite ends of the same rope and pull the other toward him. The magnitude of Hank's acceleration is 1.26 times greater than the magnitude of Harry's acceleration. What is the ratio of Hank's mass to Harry's mass?
Answer:
the ratio of Hank's mass to Harry's mass is 0.7937 or [ 0.7937 : 1
Explanation:
Given the data in the question;
Hank and Harry are two ice skaters, since both are on top of ice, we assume that friction is negligible.
We know that from Newton's Second Law;
Force = mass × Acceleration
F = ma
Since they hold on to opposite ends of the same rope. They have the same magnitude of force |F|, which is the same as the tension in the rope.
Now,
Mass[tex]_{Hank[/tex] × Acceleration[tex]_{Hank[/tex] = Mass[tex]_{Henry[/tex] × Acceleration[tex]_{Henry[/tex]
so
Mass[tex]_{Hank[/tex] / Mass[tex]_{Henry[/tex] = Acceleration[tex]_{Henry[/tex] / Acceleration[tex]_{Hank[/tex]
given that; magnitude of Hank's acceleration is 1.26 times greater than the magnitude of Harry's acceleration,
Mass[tex]_{Hank[/tex] / Mass[tex]_{Henry[/tex] = 1 / 1.26
Mass[tex]_{Hank[/tex] / Mass[tex]_{Henry[/tex] = 0.7937 or [ 0.7937 : 1 ]
Therefore, the ratio of Hank's mass to Harry's mass is 0.7937 or [ 0.7937 : 1 ]
Why do you think we see the sun moves across the sky?
answer it for brainlliest
Answer:
From Earth, the Sun looks like it moves across the sky in the daytime and appears to disappear at night. This is because the Earth is spinning towards the east. The Earth spins about its axis, an imaginary line that runs through the middle of the Earth between the North and South poles.
The figure shows a graph of the angular velocity of a rotating wheel as a function of time. Although not shown in the graph, the angular velocity continues to increase at the same rate until t = 8.6 s. What is the angular displacement of the wheel from 0 to 8.6 s?
Answer:
θ = 33.54 rad
Explanation:
This is a circular motion exercise
θ= θ₀ + w₀ t + ½ α t²
suppose that for t = 0 the body is at its initial point θ₀ = 0 and from the graph we see that the initial angular velocity w₀ = -9.0 rad / s
we look for the angular acceleration,
α = [tex]\frac{\Delta w}{ \Delta t}[/tex]
from the graph taken two points
α = [tex]\frac{0 - (-9.0)}{3.0 - 0}[/tex]
α = 3 rad / s²
we substitute in the first equation
θ = 0 -9 t + ½ 3 t²
the displacement is requested for t = 8.6 s
θ = = -9 8.6 + 3/2 8.6²
θ = 33.54 rad
The angular displacement of the wheel from 0 to 8.6s is 33 radians.
Given to us
t = 8.6s
Acceleration of the wheelWe know acceleration is the ratio of velocity and time, therefore, the slope of the velocity-time graph will give us acceleration, therefore,
At point t=3, ω = 0
At point t = 5, ω = 6
Acceleration = slope of the Velocity-time graph = 3 rad/sec²
Angular displacementUsing the equation,
[tex]\theta = \omega_0t+\dfrac{1}{2}\alpha t^2[/tex]
SUbstitute values,
[tex]\theta = (-9.0\times 8.6)+\dfrac{1}{2}(3\times 8.6^2)\\\theta = 33\rm\ radians[/tex]
Hence, the angular displacement of the wheel from 0 to 8.6s is 33 radians.
Learn more about Angular displacement:
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If a duster is left on the top of the chalkboard, it is said to possess kinetic energy.
Answer:
In the above diagram, we move by horizontally with a velocity to the right. But due to gravity the hand falls a distance as we move .
Therefore the time it takes to fall by a distance is given by =.
If = as →∞, then from the laws of motion
=12()22
Therefore for the whole journey from left to right our muscle has to give a beat up at an amount equal to the gravity force. So, the work supplied by the muscle for one trip would be
∫=∫012()22
A man is going to rub the chalk off a blackboard, he is going to choose a way to rub off the chalk in two ways
Starting from the upper left corner of the board and moving horizontally to the right and moving slightly down and then again moving to the right and then when it reaches the left corner and so on
The second way is given in the following: He starts at the top and rubs down and then up again and so on.
He is going to choose the way that is less tiring in his arms. i.e., less work done by his muscles!
Somehow from vague intuitive notion I am inclined to agree that it would be less tiring to rub off the chalk if he moves the duster beginning at the top and rubbing horizontally and gradually decreasing the height when one reach the corners till everything is off.
I tried to calculate the muscle work by considering the following ideas(please correct me if I'm wrong):
The nerves inside our muscle has to fire its signal continuously throughout the entire interval of the process of rubbing and its has to oppose the gravitational force keeping the hand up the air.
When the hand is at the highest point on the blackboard, the muscle has to work against gravity =, as the muscle continues to work against gravity throughout the interval from left to right (the horizontal path of the first case) I couldn't find the total work withstood by our muscle.
A puck moves 2.35 m/s in a -22.0 direction. A hockey stick pushes it for 0.215 s, changing its velocity to 6.42 m/s in a 50 degree direction. What was the direction of the acceleration?
Answer:
48.9 is the answer I think !
Answer:
28.4
Explanation:
(4.56 x 10^-13)-(1.17 x 10^-13)
CHEGG A neutron star has a mass of 2.08 × 1030 kg (about the mass of our sun) and a radius of 6.73 × 103 m. Suppose an object falls from rest near the surface of such a star. How fast would it be moving after it had fallen a distance of 0.0093 m? (Assume that the gravitational force is constant over the distance of the fall, and that the star is not rotating.
Let g be the acceleration due to gravity on the surface of the star. By Newton's second law, the gravitational force felt by the object has a magnitude of
F = GMm/r ² = mg
where
• G = 6.67 × 10⁻¹¹ Nm²/kg² is the gravitational constant,
• M = 2.08 × 10³⁰ kg is the mass of the star,
• m is the unknown mass of the object, and
• r = 6.73 × 10³ m is the radius of the star
Solving for g gives
g = GM/r ²
g = (6.67 × 10⁻¹¹ Nm²/kg²) (2.08 × 10³⁰ kg) / (6.73 × 10³ m)²
g ≈ 3.06 × 10¹² m/s²
The object is in free fall with uniform acceleration and starting from rest, so its speed after falling 0.0093 m is v such that
v ² = 2g (0.0093 m)
v = √(2g (0.0093 m))
v ≈ 240,000 m/s ≈ 240 km/s
Mark pushes his broken car 140 m down the block to his friend's house. He has to exert a 110 N horizontal force to push the car at a constant speed. How much thermal energy is created in the tires and road during this short trip?
Answer:
Explanation:
This is a work problem...energy is created and used in the form of work.
W = FΔx where W is work, F is the force needed to move the object Δx in meters.
W = 110(140) ∴
W = 15000 J
The total mass of the wheelbarrow and the road is 80 kg calculate the weight of the wheelbarrow and the road
Force required to lift the wheelbarrow
Answer:
The weight of the wheelbarrow and the road is 784 N and the force required to lift the wheelbarrow is 784 N.
Explanation:
Given that,
The total mass of the wheelbarrow and the road is 80 kg.
The weight of an object is given by :
W = mg
where
g is acceleration due to gravity
So,
W = 80 × 9.8
= 784 N
So, the force required to lift the wheelbarrow is equal to its weight i.e. 784 N.
a ball is projected horizontally from the top of a hill with a velocity of 30 m per second if it reaches the ground 5 seconds later the height of the hill is
Answer:
The height of the hill is 125m.
Explanation:
Since the ball is projected horizontally from the top of a hill, there is no vertical component of the velocity of projection. Therefore, so far as motion in the vertical direction is concerned, the ball is just dropped, ie its initial velocity u is merely 0 m/s. It reaches the ground after 5 seconds from the moment of projection, under the action of accerelation due to gravity.
Using,
s = u t + ½ a t². In this expression u= 0 m/s, a = 10m/s², t = 5 s. Substituting in the equation we get,
s = 0× t + ½ ×10 m/s²× 5²s²= 5× 25 m = 125m.
Consider a point on a bicycle wheel as the wheel turns about a fixed axis, neither speeding up nor slowing down. Compare the linear and angular accelerations of the point.
a. Both are zero.
b. Only the angular acceleration is zero.
c. Only the linear acceleration is zero.
d. Neither is zero
Explain your choice
Answer:
c. Only the linear acceleration is zero.
Explanation:
The linear acceleration is defined as the rate of change of linear velocity. Since the bicycle is moving in the same direction, with the same speed, without speeding up or slowing down. Therefore, there will be no change in linear velocity and as a result, linear acceleration will be zero.
The angular acceleration is the rate of change of angular velocity. Since the angular velocity is changing its direction constantly. Therefore, it has a certain component of acceleration at all times called centripetal acceleration.
Therefore, the correct option is:
c. Only the linear acceleration is zero.
A bowling ball with a mass of 8 kg is moving at a speed of 5 m/s. What is its
kinetic energy?
Answer:
100J
Explanation:
Kinetic energy=1/2mv^2
Kinetic energy=(1/2 x 8)x5^2
Kinetic energy=4x25
Kinetic energy=100
100J
Define reversible change
Answer:
Reversible changes are changes that can be undone or reversed. Melting, freezing, boiling, evaporating, condensing, dissolving and also, changing the shape of a substance are examples of reversible changes. If playback doesn't begin shortly, try restarting your device.
Explanation:
Answer:
A reversible change is a change that can be undone or reversed.
Explanation:
A 30g bullet at v=900m/s strikes a 1kg soft iron target stopping inside the iron [c=490J/kg°C. How much will the temperature of the iron increase? Ignore the heat that will be shared with the bullet
A) 25°C
B) 24795°C
C) 826°C
D) 82653°C
show your full work please
Answer:
ΔT = 25°C
Explanation:
Given that.
The mass of a bullet, m₁ = 30 g = 0.03 kg
The speed of the bullet, v = 900 m/s
Mass of soft iron, m₂ = 1 k
The specific heat of iron, c=490J/kg°C
We need to find the increase in temperature of iron. using the conservation of energy,
Kinetic energy = heat absorbed
[tex]\dfrac{1}{2}m_1v^2=m_2c\Delta T\\\\\Delta T=\dfrac{\dfrac{1}{2}m_1v^2}{m_2c}\\\\\Delta T=\dfrac{\dfrac{1}{2}\times 0.03\times 900^2}{1\times 490}\\\\=24.79^{\circ} C\\\\or\\\\\Delta T=25^{\circ} C[/tex]
So, the correct option is (A).
