1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Ber [7]
2 years ago
5

A child is riding in a child-restraint chair, securely fastened to the seat of a car. Assume the car has speed 47 km/h when it h

its a tree and is brought to rest in 0.20 s.The mass of the child is 19 kg.Assuming constant deceleration during the collision, estimate the net horizontal force that the straps of the restraint chair exert on the child to hold her in the chair.
Physics
1 answer:
Elina [12.6K]2 years ago
5 0

Answer: F = 1235 N

Explanation: Newton's Second Law of Motion describes the effect of mass and net force upon acceleration: F_{net}=m.a

Acceleration is the change of velocity in a period of time: a=\frac{\Delta v}{\Delta t}

Velocity of the car is in km/h. Transforming it in m/s:

v=\frac{47.10^{3}}{36.10^{2}}

v = 13 m/s

At the moment the car decelerates, acceleration is

a=\frac{13}{0.2}

a = 65 m/s²

Then, force will be

F_{net}=19(65)

F_{net} = 1235 N

The horizontal net force the straps of the restraint chair exerted on the child to hold her is 1235 newtons.

You might be interested in
A 190 g glider on a horizontal, frictionless air track is attached to a fixed ideal spring with force constant 160 N/m. At the i
laiz [17]

(a) Let <em>x</em> be the maximum elongation of the spring. At this point, the glider would have zero velocity and thus zero kinetic energy. The total work <em>W</em> done by the spring on the glider to get it from the given point (4.00 cm from equilibrium) to <em>x</em> is

<em>W</em> = - (1/2 <em>kx</em> ² - 1/2 <em>k</em> (0.0400 m)²)

(note that <em>x</em> > 4.00 cm, and the restoring force of the spring opposes its elongation, so the total work is negative)

By the work-energy theorem, the total work is equal to the change in the glider's kinetic energy as it moves from 4.00 cm from equilibrium to <em>x</em>, so

<em>W</em> = ∆<em>K</em> = 0 - 1/2 <em>m</em> (0.835 m/s)²

Solve for <em>x</em> :

- (1/2 (160 N/m) <em>x</em> ² - 1/2 (160 N/m) (0.0400 m)²) = -1/2 (0.190 kg) (0.835 m/s)²

==>   <em>x</em> ≈ 0.0493 m ≈ 4.93 cm

(b) The glider attains its maximum speed at the equilibrium point. The work done by the spring as it is stretched away from equilibrium to the 4.00 cm position is

<em>W</em> = - 1/2 <em>k</em> (0.0400 m)²

If <em>v</em> is the glider's maximum speed, then by the work-energy theorem,

<em>W</em> = ∆<em>K</em> = 1/2 <em>m</em> (0.835 m/s)² - 1/2 <em>mv</em> ²

Solve for <em>v</em> :

- 1/2 (160 N/m) (0.0400 m)² = 1/2 (0.190 kg) (0.835 m/s)² - 1/2 (0.190 kg) <em>v</em> ²

==>   <em>v</em> ≈ 1.43 m/s

(c) The angular frequency of the glider's oscillation is

√(<em>k</em>/<em>m</em>) = √((160 N/m) / (0.190 kg)) ≈ 29.0 Hz

3 0
2 years ago
A student wants to determine the impulse delivered to the lab cart when it runs into the wall. The student measures the mass of
forsale [732]
Impulse = Force * times and also Impulse = change in momentum.

Given that the mass does not change, change if momentum = mass * (final velocity -  initial velocity)

Given that you know mass and initial velocity (which is the velicity before the cart hits the wall) you need the final velocity (which is the velocity after the cart hits the wall).

Answer: the velocity of the cart after it hits the wall.
6 0
3 years ago
How to create or build a homemade golf club. is this possible? If so, what suggestion did you find? Do you have an original idea
goldenfox [79]

Answer:

All you need is golfing equipment make a small hole in the ground and have like something to cover the sun off of you and boom you got a golfing spot and a golf club no skills needed. Oh and you need a small flag for your gold hole but then your good and you can have fun

Explanation:

8 0
2 years ago
A constant force of 11.8 N in the positive x direction acts on a 4.7-kg object as it moves from the origin to the point (1.6i –
zhenek [66]

Answer:

W = 18.88 J

Explanation:

Given that,

Constant force, F = 11.8 N (in +x direction)

Mass of an object, m = 4.7 kg

The object moves from the origin to the point (1.6i – 4.6j) m

We need to find the work is done by the given force during this displacement. The work done by an object is given by the formula as follows :

W=F{\cdot} d\\\\W=(11.8i){\cdot} (1.6i-4.6j)\\\\=11.8\times 1.6\\\\=18.88\ J

So, the work done by the given force is 18.88 J.

5 0
2 years ago
A speaker vibrates at a frequency of 200 hz what is its period
Norma-Jean [14]

Period = (1) / (frequency)

Period = (1) / (200 per second)  =  0.005 second  =  5 milliseconds

5 0
3 years ago
Read 2 more answers
Other questions:
  • Meg goes swimming on a hot afternoon. When she comes out of the pool, her foot senses that the pavement is unbearably hot. Suppo
    10·2 answers
  • What is the wavelength of a wave that has a speed of 3 km/s and a frequency of 12 Hz? A. 36 km B. 3.6 km C. 0.25 km D. 4 km
    11·1 answer
  • What is the acceleration of a 0.30-kg volleyball when a player uses a force of 42 N to spike the ball?
    10·1 answer
  • Two tiny conducting spheres are identical and carry charges of -18.4 µC and +53.0 µC. They are separated by a distance of 2.73 c
    7·1 answer
  • Which of these statements partially defines law?
    5·1 answer
  • Honey bees can acquire a small net charge on the order of 1 pC as they fly through the air and interact with plants. Estimate th
    10·1 answer
  • The unit of electric current is the _____.<br><br> A) volt<br> B) ohm<br> C) ampere<br> D) faraday
    14·2 answers
  • Dos cargas q_1=-8μC y q_2=13μC se encuentran a una distancia r=0.12 m. ¿Cuál es la fuerza resultante sobre una tercera carga q_3
    5·1 answer
  • 5. Three children are at work. One is pushing a chair, another is pushing the sofa and the third one is pushing an empty trolley
    10·1 answer
  • What is the weight of a 82.1 kg object on Jupiter, where the acceleration due to gravity is 24.5 m/s2?
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!