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Musya8 [376]
3 years ago
5

A child whose weight is 276 N slides down a 5.90 m playground slide that makes an angle of 34.0° with the horizontal. The coeffi

cient of kinetic friction between slide and child is 0.130. (a) How much energy is transferred to thermal energy? (b) If she starts at the top with a speed of 0.518 m/s, what is her speed at the bottom?
Physics
2 answers:
givi [52]3 years ago
5 0

Answer:

Explanation:

weight of child, mg = 276 N

distance, s = 5.90 m

angle of inclination, θ = 34°

coefficient of kinetic friction, μk = 0.130

(a)

The work done by the friction force is converted into heat.

W = μk x mg x Cos θ x s

W = 0.130 x 276 x Cos 34° x 5.90

W = 175.5 Joule

Thus, the amount of thermal energy is 175.5 Joule.

(b)

initial speed, u = 0.518 m/s

Let the speed at the bottom is v.

let the acceleration is a.

a = g Sinθ - μk g Cosθ

a = 9.8 (Sin 34 - 0.130 x Cos 34)

a = 9.8 (0.559 - 0.108)

a = 4.42 m/s

Use III equation of motion

v² = u² + 2 a s

v² = 0.518 x 0.518 + 2 x 4.42 x 5.9

v² = 0.2683 + 52.156

v = 7.24 m/s

garik1379 [7]3 years ago
4 0

Answer:

Explanation:

Frictional force acting on the child = μ mg cosθ

, μ is coefficient of kinetic friction ,  m is mass of child θ is inclination

work done by frictional force

μ mg cosθ x d , d is displacement on inclined plane

work done = .13 x 276 x cos34 x 5.9

= 175.5 J

This work will be converted into heat energy.

b ) Initial energy of child = mgh + 1/2 m v ² , h is height , v is initial velocity

= 276 x 5.9 sin34  + 1/2 x 276 / 9.8 x .518² [ mass m = 276 / g ]

= 910.59 + 3.77

= 914.36 J

loss of energy due to friction = 175.5

Net energy at the bottom

= 738.86 J

If v be the velocity at the bottom

1/2 m v² = 738 .86

.5 x (276 / 9.8) x v² = 738.86

v² = 52.47

v = 7.24 m /s .

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Mademuasel [1]

According to Newton's Second Law of Motion :

The Force acting on an Object is equal to Product of Mass of the Object and Acceleration produced due to the Force.

:\implies  Force acting = Mass of the Object × Acceleration

Given : Force = 50 newton and Mass of the Object = 10 kg

Substituting the respective values in the Formula, we get :

:\implies  50 N = 10 kg × Acceleration

:\implies \mathsf{Acceleration = \dfrac{50\;N}{10\;kg}}

:\implies Acceleration of the Object = 5 m/s²

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3 years ago
A car accelerates from rest at a rate of 6.50 m/s2. Determine thevelocity of the car at t = 4.00 s.
aksik [14]

Answer:

1.62 m/s2

Explanation:

6.50 divided by 4

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2 years ago
The weight of an astronaut plus his space suit on the Moon is only 250 N. (a) How much does the suited astronaut weigh on Earth?
Evgesh-ka [11]

Answer:

a)1500N

b)153.06kg

Explanation:

F = ma

g(moon) = is the acceleration due to gravity on the moon

g(earth) is the acceleration due to gravity on the earth

g(moon) = 1/6g(earth)

g(earth) =6g(moon)

F(gearth) = mg(earth)

               = m 6g(moon)

               = 6 × 250

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b) F(gearth) = mg(earth)

m = F /g

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3 0
3 years ago
Read 2 more answers
a) Calculate the magnitude of displacement of the car in 40 seconds. b) During which part of the journey was the car acceleratin
Zielflug [23.3K]

Answer:

a)  600 meters

b) between 0 and 10 seconds, and between 30 and 40 seconds.

c) the average of the magnitude of the velocity function is 15 m/s

Explanation:

a) In order to find the magnitude of the car's displacement in 40 seconds,we need to find the area under the curve (integral of the depicted velocity function) between 0 and 40 seconds. Since the area is that of a trapezoid, we can calculate it directly from geometry:

Area \,\,Trapezoid=(\left[B+b]\,(H/2)\\displacement= \left[(40-0)+(30-10)\right] \,(20/2)=600\,\,m

b) The car is accelerating when the velocity is changing, so we see that the velocity is changing (increasing) between 0 and 10 seconds, and we also see the velocity decreasing between 30 and 40 seconds.

Notice that between 10 and 30 seconds the velocity is constant (doesn't change)  of magnitude 20 m/s, so in this section of the trip there is NO acceleration.

c) To calculate the average of a function that is changing over time, we do it through calculus, using the formula for average of a function:

Average\,of\,f(x)=\frac{1}{b-a} \int\limits^b_a {f(x)} \, dx

Notice that the limits of integration for our case are 0 and 40 seconds, and that we have already calculated the area under the velocity function (the integral) in step a), so the average velocity becomes:

Avearage=\frac{600\,\,m}{40\,\,s}= 15\,\,\frac{m}s}

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Answer:

A switch opens or closes the electrical circuit, turning the flow of electricity on or off.

Explanation:

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