Answer:
The value of acceleration that accomplishes this is 8.61 ft/s² .
Explanation:
Given;
maximum distance to be traveled by the car when the brake is applied, d = 450 ft
initial velocity of the car, u = 60 mph = (1.467 x 60) = 88.02 ft/s
final velocity of the car when it stops, v = 0
Apply the following kinematic equation to solve for the deceleration of the car.
v² = u² + 2as
0 = 88.02² + (2 x 450)a
-900a = 7747.5204
a = -7747.5204 / 900
a = -8.61 ft/s²
|a| = 8.61 ft/s²
Therefore, the value of acceleration that accomplishes this is 8.61 ft/s² .
What do these two changes have in common?
baking cookies
making paper from wood
Select all that apply.
Which of the following statements describe a perfectly in elastic collision
A) two billiard balls bounce off each other
B) a wad of chewing gum is thrown and sticks to a moving truck
C)Two ice skaters hit each other and fall over in opposite directions
D) a car crashes into a tree and rebounds in the other direction
Answer:
B
Explanation:
A radio station can be heard if the receiver is tuned to a frequency of 6x10^5 Hz. What is the wavelength of the radio waves
5 * 10² m
Explanation:We are Given:
Frequency of the wave = 6 * 10⁵ Hz
Wavelength of the wave:
We know the relation:
c = λν
[where λ (Lambda) is the wavelength ,ν (nu) is the frequency and c is the speed of light ]
3 * 10⁸ m/s= (6 * 10⁵ )* λ [replacing known values]
λ = [tex]\frac{3 * 10^{8}}{6 * 10^{5}}[/tex] [dividing both sides by 6 * 10⁵]
λ = 1/2 * 10³
λ = 1/2 * 10 * 10² [10³ can be rewritten as 10 * 10²]
λ = 5 * 10² m
Therefore, the wavelength of the wave is 5 * 10² m
Consider a block sliding down a ramp whose motion is opposed by frictional forces. The total energy of this system is modeled by the equation:
Etotal = 1/2mv^2 + mgh + Ff(f is underscore)d
Which part of the equation represents the amount of energy converted to thermal energy?
A. mg
B. Ffd
C. mgh
D. 1/2 mv^2
Answer:
Do you have the answers for the unit 6 test?
Explanation:
PLZ
please help, what's the efficiency of the two pulleys
Answer:20cm
Explanation:
There is gravitational force on the Earth from the Sun, and a gravitational force on the Sun from the Earth. Which pulls harder?
Answer:
They both pull the same amount. For every force there is an equal and opposite force.
Explanation:
5.
State the number of significant digits in each measurement and
express the value in scientific notation.
a. 110 m
f. 20.40 m/s
b. 0.2°C
g0.71 ns
c. 0.090 11 kg
h. 0.06 kg
d. 52.5 X 10 - 3
7040 m
600.0 N
וורן
e.
Answer:
Tanong mo po sa guro mo welcome pasensya need ko po ng point
A potential difference of 5v is used to produce a current of 4A for 4 hours through a heating coil. What is the heat produced.
a 80j
b 4.8kj
c 20j
d 4800kj
Answer:
Explanation:
Heat generated by the coil is expressed as;
Heat generated = Power ×Time
Heat generated = IVt
I is the current = 4A
V is the voltage= 5V
t is the time = 4hrs
Convert to secs
t = 4(3600) = 14400secs
Substitute into the formula
Heat generated = 4×5×14400
Heat generated = 20×14400
Heat generated = 288000Joules
Heat generated =288KJ
Which of the following is the main idea of Thomas Paine's "Common Sense"?
A model of a helicopter rotor has four blades, each 3.4 m in length from the central shaft to the tip of the blade. The model is rotated in a wind tunnel at 550 rev/min. What is the radial acceleration of the blade tip, expressed as a multiple of the acceleration g due to gravity?
A. (5.72 × 104)g
B. (6.23 × 102)g
C. (1.15 × 103)g
D. (2.25 × 103)g
A rock dropped from a 5 m height accelerates at 10 m/s and strikes the ground 1 s later. If the rock is dropped
from a height of 2,5 m, its acceleration of fall is
Answer:
10 m/s²
Explanation:
The above question simply indicates motion under gravity.
The acceleration due to gravity (i.e acceleration of free fall) has a constant value of 10 m/s².
Whether the rock is dropped from a height of 5 m or 2.5 m, it will accelerate at 10 m/s² before striking the ground. The only thing that will be different is the time taken for the rock to strike the ground when released from both 5 m and 2.5 m.
Thus, the rock will have a constant acceleration of 10 m/s² irrespective of the height to which it was released.
Since acceleration due to gravity is a constant, the acceleration of the rock dropped from the 5 m height is the same as that dropped from the 2.5 m height and is equal to 10 m/s²
What is the acceleration due to gravity?Acceleration due to gravity is the acceleration a body falling freely from a height above the earth surface which a body experiences due to the gravitational force of attraction of the earth on the body.
Acceleration due to gravity has a constant value which is equal to 10 m/s².
Therefore, the acceleration of the rock dropped from the 5 m height is the same as that dropped from the 2.5 m height and is equal to 10 m/s².
Learn more about acceleration due to gravity at: https://brainly.com/question/11873969
Find an expression for the kinetic energy of the car at the top of the loop.Express the kinetic energy in terms of m, g, h, and R.
Answer:
K.E₂ = mg(h - 2R)
Explanation:
The diagram of the car at the top of the loop is given below. Considering the initial position of the car and the final position as the top of the loop. We apply law of conservation of energy:
K.E₁ + P.E₁ = K.E₂ + P.E₂
where,
K.E₁ = Initial Kinetic Energy = (1/2)mv² = (1/2)m(0 m/s)² = 0 (car initially at rest)
P.E₁ = Initial Potential Energy = mgh
K.E₂ = Final Kinetic Energy at the top of the loop = ?
P.E₂ = Final Potential Energy = mg(2R) (since, the height at top of loop is 2R)
Therefore,
0 + mgh = K.E₂ + mg(2R)
K.E₂ = mg(h - 2R)
The kinetic energy of the car is expressed as K.E = mg(h - 2R). The energy of the object by the integrity of its movement is understood as kinetic energy.
What is kinetic energy?The energy of the body by the virtue of its motion is known as the kinetic energy of the body. It is defined as the product of half of mass and square of velocity.
The following data is observed from the figure;
K.E₁ = Initial Kinetic Energy = (1/2)mv² = (1/2)m(0 m/s)² = 0
P.E₁ = Initial Potential Energy = mgh
K.E₂ = Final Kinetic Energy at the top of the loop =?
P.E₂ = Final Potential Energy = mg(2R) (since, the height at top of loop is 2R)
According to the law of conservation of energy, total energy is defined as the sum of kinetic energy and potential energy.
Total energy = kinetic energy+potential energy
On applying the law of conservation of energy for top and bottom of the loop;
K.E₁ + P.E₁ = K.E₂ + P.E₂
0 + mgh = K.E₂ + mg(2R)
K.E₂ = mg(h - 2R)
Hence the kinetic energy of the car is expressed as K.E = mg(h - 2R).
To learn more about kinetic energy refer to the link;
brainly.com/question/999862
Heidi (39 kg) is walking her tiny chihuahua, Chaxi (5.60 kg), on the sidewalk. To encourage Chaxi along, Heidi pulls forward with a force of 9.55 N. Identify the correct reaction force in response to Heidi’s action force.
a. The friction is less than 660 N since the beam can be moved at a constant velocity.
b. There is no friction acting on the beam since it is accelerating.
c. The friction is equal to 660 N since the beam is not accelerating.
d. The friction is greater than 660 N since the beam is not in equilibrium.
Answer:
The correct reaction force in response to Heidi's action force is:
c. The friction is equal to 660 N since the beam is not accelerating.
Explanation:
Heidi's action force does not affect the beam. Since friction resists the sliding or rolling of one solid object over another, there is no friction acting on the beam, in this respect. The reaction force is what makes the dog to move because it acts on it. According to Newton's Third Law of Motion, forces always come in action-reaction pairs. This Third Law states that for every action force, there is an equal and opposite reaction force. This means that the dog exerts some force on Heidi, as he pulls it "forward with a force of 9.55 N."
A peregrine falcon dives at pigeon . the falcon start downward from rest with free-fall acceleration . if the pigeon is 76.0 m below the initial position of the falcon , how long the falcon take to reach the pigeon? Assume that the pigeon remains at rest .
Answer:
3.94 s
Explanation:
Take down to be positive. Given:
Δy = 76.0 m
v₀ = 0 m/s
a = 9.8 m/s²
Find: t
Δy = v₀ t + ½ at²
76.0 m = (0 m/s) t + ½ (9.8 m/s²) t²
t = 3.94 s
A plane is heading due west and climbing at the rate of 80 km/hr. If its airspeed is 540 km/hr and there is a wind blowing 80 km/hr to the northwest, what is the ground speed of the plane?
Answer:
599.245km/hr
Explanation:
A plane is heading due west and climbing at the rate of 80 km/hr. If its airspeed is 540 km/hr and there is a wind blowing 80 km/hr to the northwest, what is the ground speed of the plane?
We solve the above question using vectors
In vector form Air speed is -540i + 0j Wind speed is (-80/√2)i + (80/√2)j
Vector notation wind speed is given as: -56.5685 i + 56.5685j
The vector for the ground speed of the plane =
-540i + 0j -56.5685i + 56.5685j
= -596.56854249i + 56.5685j
The the ground speed of the plane √[(596.56854249)² + (56.5685)²]
= √359094.021081 km/hr
= 599.24454197 km/hr
Approximately
= 599.245km/hr
which of the following elements is the most reactive? Chlorine Bromine Fluorine Helium
Answer:
Fluorine is the most reactive
Explanation:
Among the halogens, fluorine, chlorine, bromine, and iodine, fluorine is the most reactive one. It forms compounds with all other elements except the noble gases helium (He), neon (Ne) and argon (Ar), whereas stable compounds with krypton (Kr) and xenon (Xe) are formed.
Measurements of the radioactivity of a certain isotope tell you that the decay rate decreases from 8255 decays per minute to 3110 decays per minute over a period of 4.50 days.
What is the half-life (T1/2) of this isotope?
Answer:half-life (T1/2) of this isotope =
Explanation:
The number of nuclei of any radioactive substance at a given time is expressed by
Nt = N0e⁻kt
Nt=decay of material at a time t, =3110 decays per minute
N=decays at t=0, 8255 decays per minute
k=constant
Nt=N0e−kt
3110= 8255 e⁻k(4.50)
3110/ 8255=e−k(4.50)
0.3767 = e−k(4.50)
In 0.3767 = -k (4.50)
0.976=-4.5k
k=0.976/4.5
=0.2159
Also we know that t 1/2= time that it takes half the original material to decay.it is related to the rate constant by
T₁/₂=ln 2 / k
Therefore half-life (T1/2) of this isotope
T₁/₂=ln 2/0.2159
T₁/₂=3.12 days
Which current is produced in homes
Answer:
answer is C on edge 2021
Explanation:
The the figure shows a famous roller coaster ride. You can ignore friction. If the roller coaster leaves Point Q from rest, what is its speed at the top of 25 m peak(Point s
Answer:
22 m/s
Explanation:
PEf +KEf =PE0 +KE0 →PE0 −PEf =KEf
−mgΔy= 1 mv2 →v= −2gΔy = −2(9.8 m/s2)(−25 m)=22 m/s
You are a guest magician in a circus. One of your tricks is to place a football on an inclined plane without the football rolling over. How can you achieve this?
Determine if the weight of the football is needed for you to prevent the football from rolling over. The coefficient of static friction of the plane is 0.067.
Answer:
You are a guest magician in a circus. One of your tricks is to place a football on an inclined plane without the football rolling over is explained below in details.
Explanation:
spinning ball halts after traveling some range due to friction energy act different direction of movement of the ball. you can observe in the figure.
Let any rolling ball of mass (m ) is traveling with velocity v ,
common effect on ball (N) = mg
because of motion, friction energy develops on the contact exterior and begins to resist the movement of the rolling ball.
hence,
fr = uN = umg act on communicating exterior, so, after any time due to friction energy rolling ball gets to rest.
A large pizza is cut into 8 even slices. A person orders 4 large pizzas from a restaurant. How many total slices of pizza did the person order?
Answer:
32 slicesExplanation:
Step one:
given data
we are told that 1 large pizza can be cut into 8 even slices
Required
we want to find how many slices are there in 4 large pizzas
Step two:
so if 1 pizza has 8 slices
4 pizza will have x
cross multiply we have
x= 8*4
x=32 slices
How safe is Wind Energy? Use in your own words.
Answer:
wind energy is safe
Explanation:
because it just is
Answer:
Wind energy isn't perfect, but better than the alternatives. There is a risk of falling off a turbine in maitenence and there are instances where birds fly into the blades, however there are far more casualties as a result of coal and other fossil fuel extraction.
Explanation:
A simple pendulum has a period T on Earth. If it were used on Planet X and found to have a period of only 71% of T, what would be the free fall acceleration due to gravity on this planet X?
Answer:
gₓ = 1.4 g = 13.8 m/s²
Explanation:
The time period of simple pendulum on earth is given as:
T = 2π√(L/g)
where,
L = Length of pendulum
g = acceleration due to gravity on the surface of earth = 9.8 m/s²
T = Time Period on Earth
but, on the other planets, it becomes:
Tₓ = 2π√(L/gₓ)
where,
Tₓ = Time Period on Surface of Other Planet
gₓ = acceleration due to gravity on other planet = ?
It is given that:
Tₓ = 71% of T
Tₓ = 0.71 T
using values:
2π√(L/gₓ) = (0.71) 2π√(L/g)
√(1/gₓ) = (0.71)√(1/g)
squaring both sides:
1/gₓ = 0.71/g
gₓ = g/0.71
gₓ = 1.4 g = 13.8 m/s²
It increases, f = ma both mass and acceleration are directly proportional to force so if mass is constant acceleration must increase to increase the force.
Answer:
is that a question?
Explanation:
thankyou for the points
A 715 kg car stopped at an intersection is rear-ended by a 1490 kg truck moving with a speed of 12.5 m/s. If the car was in neutral and its brakes were off, so that the collision is approximately elastic, find the final speed of both vehicles after the collision.
Answer:
The final velocity of the car is 16.893 m/s
The final velocity of the truck is 4.393 m/s
Explanation:
Given;
mass of the car, m₁ = 715 kg
mass of the truck, m₂ = 1490 kg
initial velocity of the car, u₁ = 0
initial velocity of the truck, u₂ = 12.5 m/s
let the final velocity of the car, = v₁
let the final velocity of the truck, = v₂
Apply the principle of conservation of linear momentum for elastic collision;
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂
(715 x 0) + (1490 x 12.5) = 715v₁ + 1490v₂
18625 = 715v₁ + 1490v₂ -----equation (1)
Apply one-directional velocity formula;
u₁ + v₁ = u₂ + v₂
0 + v₁ = 12.5 + v₂
v₁ = 12.5 + v₂
Substitute v₁ into equation (1)
18625 = 715(12.5 + v₂) + 1490v₂
18625 =8937.5 + 715v₂ + 1490v₂
18625 - 8937.5 = 715v₂ + 1490v₂
9687.5 = 2205v₂
v₂ = 9687.5 / 2205
v₂ = 4.393 m/s
solve for v₁
v₁ = 12.5 + v₂
v₁ = 12.5 + 4.393
v₁ = 16.893 m/s
Two horizontal forces, 230 N and 120 N, are exerted in opposite direction on a crate. What is the horizontal acceleration of the crate if the mass of the crate is 20 kg?
5.5 m/s2
20 m/s2
17.5 m/s2
72 m/s2
Answer:
a = 5.5 [m/s²]
Explanation:
To solve this problem we must use Newton's second law, which tells us that the force is equal to the product of mass by acceleration.
ΣF =m*a
where:
F = Force [N] (units of Newtons)
m = mass = 20 [kg]
a = acceleration [m/s²]
Let's take the force of 230 [N] as positive, in this way the other force will be negative, by pointing in the opposite direction.
[tex]230 - 120 = 20*a\\110 = 20*a\\a=5.5 [m/s^{2} ][/tex]
A ball is kicked off the ground reaching a maximum height of 60m and lands 80m away. Calculate the initial speed and the angle above the horizontal of the ball when it was kicked
Answer:
36.87°
Explanation:
Given
Maximum height = 60m
Horizontal distance (range) = 80,m
Required
Initial speed U
Angle of launch
To get the speed, we will use the range formula;
R = U √2H/g
80 = U√2(60)/9.8
80 = U√12.25
80 = 3.5U
U = 80/3.5
U = 22.86m/s
Get the angle of launch
Using the formula
Theta = tan^-1(y/x)
y is the vertical distance
x is the horizontal distance
Theta = tan^-1(60/80)
Theta = tan^-1(0.75)
Theta = 36.87°
Hence the angle of launch is 36.87°
If the speed of an object in uniform circular motion is constant and the radial distance is doubled, by what factor does the magnitude of the radial acceleration decrease?
Answer: Half
Explanation:
Given
The object is in uniform circular motion with constant speed.
Radial acceleration of the object is given by
[tex]\Rightarrow a_r=\dfrac{v^2}{r}[/tex]
Where, [tex]a_r=\text{Radial acceleration}[/tex]
[tex]v=\text{speed}\\r=\text{distance from the axis of rotation}[/tex]
If the radial distance [tex]r[/tex] is doubled, i.e. [tex]2r[/tex]
Radial acceleration is
[tex]\Rightarrow a'_r=\dfrac{v^2}{2r}\\\\\Rightarrow a'_r=\dfrac{a_r}{2}[/tex]
Radial acceleration becomes half of the initial value.
Learn more: https://brainly.in/question/21217248
true or false the melting of ice cubes is a exothermic reaction
[tex]\huge\boxed{False}[/tex]
_____________________________________ENDOTHERMIC REACTIONS:Endothermic Reaction are those reactions in which the reactants absorb the energy from their surrounding and forms the product.
_____________________________________How to know endothermic reaction?Those changes in which a substance goes from More-ordered state to less-oredered state are endothermic. Where they change from less ordered to more ordered is exothermic.
More ordered means that the movement of vibration of the particles of the substance is less and the are more close to each other. More to less ordered state is given as,
Solid>Liquid>Gas.
_____________________________________Question:In the question it asks about the melting of the ice cube. Ice cube is a solid, and when it will melt, it will change into the liquid water. As we know that, Solid is more ordered and Liquid is less ordered, and The change from more-ordered to less-ordered is endothermic thus the answer is ENDOTHERMIC.
_____________________________________Best Regards,'Borz'SI unit differ from one country to another . true or false
Answer:
false ..........false
Answer:
FALSE
Explanation: