Occupants of cars hit from behind, even at low speed, often suffer serious neck injury from whiplash. During a low‑spee rear‑end collision, a person's head suddenly pivots about the base of the neck through a 50∘ angle, a motion that lasts 220 ms.The distance from the base of the neck to the center of the head is typically about 20 cm, and the head normally comprises about 6.0% of body weight.Model the motion of the head as having a uniform speed over the course of its pivot. Compute answers to two significant figures.1. What is the acceleration ????centacent of the head during the collision?2. What force ????F does the neck exert on the head of a 65 kg65 kg person in the collision? Neglect the force of gravity on the head, and report the answer in units of both newtons and pounds.3. Would headrests mounted to the backs of the car seats help protect against whiplash? Why or why not?a. Yes. A headrest applies an upward force on the head, along the direction of the neck, that cancels the downward force applied by the neck.b. Yes. A headrest ensures that both the head and the body experience the same forward force at roughly the same time.c. No. A headrest applies a mostly horizontal force to the head, so does not affect the mostly vertical force applied by the neck during whiplash.d. No. A headrest reduces the angle traversed by the head, not the speed of the head relative to the body, thus it does not affect the force that the neck applies to the head.
Answer:
a) a= 19 m/s2, b ) F = F = 38 N
c) the correct one is B
Explanation:
1) To solve this exercise, let's use the concept of torque, let's start by looking for the mass of the mass of the head, which is 65 of 65 kg
m= 0.06 65 = 3.9 kg
torque is defined
τ = F x R
the bold indicate vectors
τ = F R sin θ
the force is the weight of the head and the distance R = 0.20 m
τ = mg R sin θ
τ = 3.9 9.8 0.2 sin 50
τ = 5.86 N m
Newton's second law expression for rotational motion is
τ = I α
In general, the head is approximated by a sphere, so the moment of foolishness with respect to the base of the neck (turning point) using the parallel axis theorem is
I = I_sphere + m d²
Neck height data is not indicated, so we will assume that it is zero (d = 0)
I = 2/5 m R²
angular and linear acceleration are related
a = α R
α = a / R
let's replace
τ = 2/5 mR² (a / R)
a = 5/2 τ / mR
let's calculate
a = 5/2 5.86 / (3.9 0.2)
a = 18.8 m / s²
a= 19 m/s²
2) as the neck and the head are related, the forces are action and reaction, therefore the neck force is
F = m g
F = 3.9 9.8 = 38.2 N
F = 38 N
3) He asks us about the efficiency of the headrest, after reviewing the different alternatives, the correct one is B
Yes. A headrest ensures that both the head and the body experience the same forward force at approximately the same time.
A cannon shoot a cannon ball. The momentum compared to the cannon ball is
Answer:
After the firing occurs, both the cannon and cannonball have the same momentum (big mass, small velocity vs. small mass, big velocity). But since the momentum for each is moving in the opposite direction, the momentums cancel out, causing the cannon-cannonball system's momentum to equal zero.
Explanation:
Social science is a branch of science that deals with the nature of
A. human society
B. the physical world
C. animal societies
D. the medical field
Answer:
A. human society
Explanation:
A 0.6 kg basketball moving 7.2 m/s to the right collides with a 0.04 kg tennis
ball moving 22 m/s to the left. After the collision, the tennis ball is moving
32.7 m/s to the right. What is the velocity of the basketball after the collision?
Assume an elastic collision occurred.
A. 10.9 m/s to the right
B. 10.9 m/s to the left
C.3.6 m/s to the left
D. 3.6 m/s to the right
Answer:b
Explanation:
The final velocity of the basketball after it undergoes collision with the tennis ball is 6.49m/s.
What is Final velocity?The final velocity is a vector quantity which measures the speed and direction of a moving object after it has reached its maximum acceleration and distance.
Given data,
mass of basket ball (m₁) = 0.6kg
mass of tennis ball (m₂) = 0.04kg
velocity of basket ball (v₁) = 7.2m/s
velocity of tennis ball (v₂) = 22m/s
velocity of basket ball (v₃) =?
velocity of tennis ball (v₄) = 32.7m/s
We already know that the expression for elastic collision is given as
m₁v₁ +m₂v₂ = m₁v₃ + m₂v₄
Substituting these values, we get
0.6 × 7.2 + 0.04 × 22 = 0.6 × x + 0.04 × 32.7
4.32 + 0.88 = 0.6x + 1.308
Solving for x we have,
3.892 = 0.6x
x = 3.892 /0.6
x=6.49m/s
Therefore, the velocity of the basketball after the collision is 6.49m/s.
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8. A dog runs with an initial speed of 7.5 m/s on a waxed floor. It slides to a stop in 15 sec. What
is the acceleration?
(10 Points)
O-7.5 m/s
-0.5 m/s2
O -7.5 m/s2
7.5 mi/hr
Answer:
-0.5 m/s²
Explanation:
Step 1: Given data
Initial velocity of the dog (u): 7.5 m/sFinal velocity of the dog (v): 0 m/s (Stop)Time elapsed (t): 15 sStep 2: Calculate the acceleration of the dog
The acceleration (a) is equal to the change in the velocity over the time elapsed.
a = v - u / t
a = 0 m/s - 7.5 m/s / 15 s
a = -0.5 m/s²
2. True or false?
Forensic entomology uses the study of insects to help criminal investigations.
Which could describe the properties of sedimentary rock?
PLASE HELP
DUE TODAY
Answer:
☝ Some of the properties of sedimentary rocks
shannon dropped his ICP textbook. how fast was it going after 3 seconds? how far did it fall? please guys help mee quickly pleaseeee
¡Hola!
For this problem, first, lets recabe information:
v = 0 m/s
t = 3 s
g = 9,82 m/s²
v' = ?
d = ?
First, for calculate the final velocity:
v' = v + g * t
v' = 0 m/s + 9,82 m/s² * 3 s
v' = 29,46 m/s [tex]\leftarrow \boxed{\text{Velocity} }[/tex]
Now, for calculate how far did it fall:
d = v * t + g * t^2 / 2
Like v = 0 m/s, we can simplificate equation:
d = g * t^2 / 2
d = 9,82 m/s² * (3 s)^2 / 2
d = 9,82 m/s² * 9 s² / 2
d = 88,38 m / 2
d = 44.19 m [tex]\leftarrow \boxed{\text{Distance} }[/tex]
¡Buena suerte!
Why is it important to warm up your muscles?
Warming up the muscles increases lactic acid build up
Warming up the muscles increases temperature and flexibility of your muscles Warming up the muscles increases your risk of injury
All of the above
Can someone please answer this
Answer:
-) It is less than 8 [N]
See the explanation below.
Explanation:
To solve this problem we must analyze each of the answers, and in this way, we will come to the right solution. The most important thing is to keep in mind that the body is moving to the left.
-) It is equal to 8 [N]
This answer is not possible, since if the Force F was equal to 8 [N] the body would be in equilibrium and the body would not move.
-) It is equal to 10 [N]
This answer is not possible, since if Force F is greater than 8 [N] the body would move to the right.
-) It is greater than 10 [N]
This answer is not possible, since if Force F is greater than 8 [N] the body would move to the right.
-) It is less than 8 [N]
This is the correct option, as the force of 8 [N] will move the body to the left.
Twin space probes have a mass of 722 kg each. If the gravitational force between the two space probes is 8.61 × 10–16 N, what is the distance between them?
Answer: d. newton.
Explanation: The SI unit of force is the
a. joule.
b. kilogram.
c. meter.
Answer:
The answer is B on edge.
Explanation:
Good day :)
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2. Identify the correct statement about the diagrams above.
O Y represents a mixture and Z represents an element.
O Y represents an compund and X represents a pure substance.
O X represents a mixture and W represents a pure substance
O W represents an element and Y represents a mixture.
Answer: W represents an element Y represents a mixture
Explanation: I just took a quiz on this and got it right. Good Luck
Click to review the online content. Then answer the question(s) below, using complete sentences. Scroll down to view additional questions.
Online Content: Site 1
How do wetlands reduce flooding and erosion? (Site 1)
Answer:
Wetlands reduce flooding and erosion by filtering water.
Explanation:
Answer:
Wetlands reduce flooding and erosion by filtering water.
Explanation:
A proposed space station includes living quarters in a circular ring 58.0 m in diameter. At what angular speed should the ring rotate so the occupants feel that they have the same weight as they do on Earth
Answer:
The angular speed [tex]w = 0.5813 \ rad/s[/tex]
Explanation:
From the question we are told that
The diameter is d = 58.0 m
Generally for the occupants feel that they have the same weight as they do on Earth then the centripetal acceleration of the circular ring must be equal to the acceleration due to gravity this can be mathematically represented as
[tex]a_c = g[/tex]
Here [tex]a_c[/tex] is the centripetal acceleration which is mathematically represented as
[tex]a_c = w^2 * r[/tex]
Here r is the radius of the circular ring
=> [tex]w^2 * r = g[/tex]
=> [tex]w = \sqrt{\frac{g}{r} }[/tex]
=> [tex]w = \sqrt{\frac{9.8}{ \frac{d}{2} } }[/tex]
=> [tex]w = \sqrt{\frac{9.8}{ \frac{58.0 }{2} } }[/tex]
=> [tex]w = 0.5813 \ rad/s[/tex]
Erica is working in the lab. She wants to remove the fine dust particles suspended in a sample of oil. Which method is she most likely to u
Answer: Option A is your answer
Explanation:
a tractor with 2000 kg of mass pulls a plow equal to 80.0 kg, exerting a 200 N force on it. The tractor and plow set moves horizontally to the right with an acceleration of 0.500 m / s2. The resistance force that the soil exerts on the plow has a modulus, in Newton, equal to?
Answer:
The resistance force that the soil exerts on the plough is 160 Newtons.
Explanation:
Fr = m.a
Fr = 80. 0,5
Fr = 40 N
Ft - F = Fr
200 - F = 40
F = 200 - 40
F = 160 Newtons
A 58.72 kg person holding a steel ball stands motionless on a frozen lake.
The person then throws the ball, which propels the person at 1.05 m/s to the
right and the ball 3.75 m/s to the left. If the initial momentum of the system is
zero, what is the mass of the steel ball?
Answer: 16.44 kg
Explanation:
What is the freezing point (in degrees Celcius) of 4.62 kg of water if it contains 236.5 g of C a B r 2
Answer:
The new freezing point of water is -0.476°C.
Explanation:
Given that,
Mass of water = 4.62 kg
Mass of CaBr₂ = 236.5 g
We need to calculate the molality of solution
Using formula of molality
[tex]m=\dfrac{mass\ of\ CaBr_{2}}{molar\ mass\ of\ CaBr_{2}\times mass\ of\ water}[/tex]
Put the value into the formula
[tex]m=\dfrac{236.5}{200\times4.62}[/tex]
[tex]m=0.256\ mol/kg[/tex]
[tex]m=0.256\ m[/tex]
We need to calculate the depression in freezing point of water
Using formula of freezing point
[tex]\Delta T=m\times k[/tex]
Where, k = depression constant
m = molality of solution
Put the value into the formula
[tex]\Delta T=0.256\times1.86[/tex]
[tex]\Delta T=0.476^{\circ}C[/tex]
We know that,
The standard freezing point of water is 0°C
We need to find the new freezing point of water
Using formula for freezing point of water
Freezing point of 4.62 kg of water = freezing point of water-depression in freezing point of water
[tex]\Delta T'=0-\Delta T[/tex]
Put the value into the formula
[tex]\Delta T'=0-0.476[/tex]
Hence, The new freezing point of water is -0.476°C.
e. A driver speeds up his vehicle while moving up a hill.
Why?
Answer:
For more acceleration
Explanation:
If he is speeding u a hill his car needs more power ecsue its going upward so he will have to speeed to gain more acceleration so his car doesnt fall
are there really dead stars in the sky?
Answer:
Yes
Explanation:
The star would have died over thousands of years ago but the light takes a long time for it to reach us on Earth.
If the breaking strength of the string is 120 N, what is the minimum angle the string can make with the horizontal
Complete Question
A 940-g rock is whirled in a horizontal circle at the end of a 1.30-m-long string, If the breaking strength of the string is 120 N, what's the minimum angle the string can make with the horizontal?
Answer:
The value is [tex]\theta = 4.41^o[/tex]
Explanation:
From the question we are told that
The mass of the rock is [tex]m_r = 940 \ g = 0.94 \ kg[/tex]
The length of the string is [tex]l = 1.30 \ m[/tex]
The breaking strength(i.e the maximum tension) on the string is [tex]T = 120 \ N[/tex]
Gnerally the vertical component of the tension experienced by the string is mathematically represented as
[tex]T_v = T sin(\theta)[/tex]
Generally this vertical component of tension is equivalent to the weight of the rock
So
[tex]Tsin (\theta) = mg[/tex]
=> [tex]\theta = sin^{-1} [\frac{mg}{ T} ][/tex]
=> [tex]\theta = sin^{-1} [\frac{0.940 *9.8 }{ 120} ][/tex]
=> [tex]\theta = 4.41^o[/tex]
How is a responding variable different from a manipulated variable?
A. When a responding variable changes, it causes the manipulated
variable to change.
B. A responding variable changes as a result of changes made to the
manipulated variable.
C. When a responding variable stays the same, the manipulated
variable changes.
O D. A responding variable changes, but a manipulated variable stays
the same.
Answer:
B. A responding variable changes as a result of changes made to the
manipulated variable.
Explanation:
A responding variable is different from a manipulated variable because a responding variable keeps on changing, but a manipulated variable stays the same. Thus, the correct option is D.
What are responding variable and manipulated variable?A variable is any characteristic, number, or quantity which can be measured or counted easily. A variable may also be called as an item. Age, sex, business income and expenses, country of birth, capital expenditure, class grades, eye color and vehicle type all are the example of variables.
Manipulated Variable are those variables which is changed by the scientist and are called as the controlled variable. Responding Variable is the variable that might change on its own because of what the scientist changes in the experimental study.
Therefore, the correct option is D.
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pleeeeeeease help asap
Name 2 activities to improve Muscular Strength. Explain what muscles these activities will improve.
Answer:
Pushups will improve your biceps. Pull ups will improve your core and abdomen
a hole is punched at a height h in the side of a container of height h0. The container is full of water. If the water is to shoot as far as possible horizontally, (a) how far from the bottom of the container should the hole be punched? (b) Neglecting frictional losses, how far (initially) from the side of the container will the water land?
rt A How much work does the electric motor of a Van de Graaff generator do to lift a positive ion (q=e) if the potential of the spherical electrode is 2.0 MV ?
Answer:
W = 2.0 MeV = 3.2*10⁻¹³ J
Explanation:
Assuming that the ion is located originally at a point where the electrostatic potential is zero, the change in energy of the ion is just the change in electrostatic potential times the charge of the ion, as follows:[tex]\Delta E = e*V = 1.6e-19 C * 2.0e6 V = 2.0 MeV = 3.2e-13 J[/tex]
This change in energy, assuming no friction present, must be equal to the work done by the motor on the ion:W = 2.0 MeV = 3.2*10⁻¹³ J.
PEOPLE PLEASE HELP ASAP!!!-How does Force effect acceleration?
Answer:
If the force is higher then the resitance o fht eobject then force will make object accelerate.
Explanation:
Does that make sense. If you need something else as an answer tell me in the comments and please mark with a heart and brainliest. If you don't mind
We know:
Force =Mass×Accerlation
[tex]∴Accerlation = \dfrac{force}{mass} [/tex]
So by seeing this formula we came to know that accerlation is directly proportional to force and inversely proportional to mass.
So by increase of force acceleration also increases.
Consider a wire of length L =0.30 m that runs north-south on a horizontal surface. There is a current I = 0.50 A flowing north in tie wire. The Earth's magnetic field at this location has a magnitude of 0.50 gauss (or, in SI units. 0.5 x 10^—4 and points north and 38 degrees down from the horizontal, toward the ground. What is the size of the magnetic force on the wire due to the Earth's magnetic field?
Answer:
The size of the magnetic force on the wire due to the Earth's magnetic field is 4.62 × 10⁻⁶ N.
Explanation:
To determine the size of the magnetic force on the wire due to the Earth's magnetic field,
The magnetic force is given by the formula
F = ILB sinθ
Where F is the magnetic force on the wire
I is the electric current in Amperes (A)
L is is the length of wire in meters (m)
B is the magnetic field in Tesla (T)
and θ is the angle between current and magnetic field
From the question,
L = 0.30 m
I = 0.50 A
B = 0.50 gauss = 0.5 × 10⁻⁴ T (NOTE: 1 Gauss = 10⁻⁴ Tesla)
θ = 38°
Now, putting the values into the equation
F = ILB sinθ
F = 0.50 × 0.30 × 0.5 × 10⁻⁴ sin38°
F = 7.5 × 10⁻⁶ (0.61566)
F = 4.62 × 10⁻⁶ N
Hence, the size of the magnetic force on the wire due to the Earth's magnetic field is 4.62 × 10⁻⁶ N.
When you bent the plastic ruler, what did you observe in its size?
Answer:
The size will increase.
Explanation:
When you bend a plastic ruler, it's size will increase because it is elastic and will exhibit elastic deformation. When it is been bent, it will continue to stretch until it get to a point where it will not be able to regain it formal shape, it size wound of increase. Therefore when the ruler get to elastic limit and you have bend it to the point it cannot regain it's formal shape back, it will remain bent and if further force is apply on it,it will break.
1/2
I, the student, verify that I have read the lab safety document and will comply with the rules as stated.
Yes
No
Suppose Tom Harmon17 is standing at the exact center of the Ohio State football field18 on the 50 yard line. The field is 300 feet long and 160 feet wide. Suppose the ball leaves Harmon’s hand at a height of six feet and has initial velocity v(0) = 40i + 39j + 32k feet per second where j points toward the sideline, i points toward the end zone, and k = i × j points straight up. The acceleration due to gravity is −32k feet per second squared and the mass of the football is .45 kilograms.
(a) Determine a parameterization for the position of the football at time t seconds after it is thrown.
(b) Suppose David Nelson19 catches the ball when it is six feet above the ground. Is Nelson in bounds or out of bounds when he catches the ball? (Assume Nelson’s toes are touching the ground directly below the ball when he catches the ball.)'
Answer:
a) x = 40 t , y = 39 t , z = 6 + 32 t - 16 t ², b) x = 80 feet , y = 78 feet , the ball came into the field
Explanation:
a) This is a projectile launch exercise, where in the x and y axes there is no acceleration and in the z axis the acceleration of the acceleration of gravity, let's write the equations of motion in each axis
Since the cast is in the center of the field, let's place the coordinate system
x₀ = 0
y₀ = 0
z₀ = 6 feet
x-axis (towards end zone, GOAL zone)
x = xo + v₀ₓ t
x = 40 t
y-axis (field width)
y = y₀ + [tex]v_{oy}[/tex] t
y = 39 t
z axis (vertical)
z = z₀ + v_{oz} t - ½ g t²
z = 6 + 32 t - ½ 32 t²
z = 6 + 32 t - 16 t ²
b) The player catches the ball at the same height as it came out, so we can find the time it takes to arrive
z = 6
6 = 6 + 32 t - 16 t²
(t - 2)t = 0
t=0 s
t= 2 s
The ball position
x = 40 2
x = 80 feet
y = 39 2
y = 78 feet
the dimensions of the field from the coordinate system (center of the field) are
x_total = 150 feet
y _total = 80 feet
so we can see that the ball came into the field