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Andre45 [30]
3 years ago
13

4) A drag racer starts her car from rest and accelerates at 10.0 m/s² for a distance of 400 m (1/4 mile). (a) How long did it ta

ke the race car to travel this distance? (b) What is the speed of the race car at the end of the run?​
Physics
1 answer:
mel-nik [20]3 years ago
3 0

Answer:

A) s=1/2at^2

t=√(2s/a)=√(2x400)/10.0)=9.0s

B) v=at

v=10.0x9=90m/s

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A Ferris wheel on a California pier is 27 m high and rotates once every 32 seconds in the counterclockwise direction. When the w
Leto [7]

A) 140 degrees

First of all, we need to find the angular velocity of the Ferris wheel. We know that its period is

T = 32 s

So the angular velocity is

\omega=\frac{2\pi}{T}=\frac{2\pi}{32 s}=0.20 rad/s

Assuming the wheel is moving at constant angular velocity, we can now calculate the angular displacement with respect to the initial position:

\theta= \omega t

and substituting t = 75 seconds, we find

\theta= (0.20 rad/s)(75 s)=15 rad

In degrees, it is

15 rad: x = 2\pi rad : 360^{\circ}\\
x=\frac{(15 rad)(360^{\circ})}{2\pi}=860^{\circ} = 140^{\circ}

So, the new position is 140 degrees from the initial position at the top.

B) 2.7 m/s

The tangential speed, v, of a point at the egde of the wheel is given by

v=\omega r

where we have

\omega=0.20 rad/s

r = d/2 = (27 m)/2=13.5 m is the radius of the wheel

Substituting into the equation, we find

v=(0.20 rad/s)(13.5 m)=2.7 m/s

6 0
3 years ago
Unpolarized light is passed through three successive polaroid filters, each with its transmission axis at 32. 8° to the precedin
Oliga [24]

The percentage of light gets through three successive polarized filters is 24.9 %

From the question,

Given that,

Angle of transmission axis = 32.8°

The intensity of light emerging from the first polarizer is determined by the equation

I₁ = I₀ / 2

where I₀ ⇒ intensity of unpolarized light

The light emerging from the second polarizer can be mathematically represented by,

I₂ = I₁ x cos²θ

Substituting the values,

I₂ =( I₀/2) x cos²θ

  = (I₀/2) x cos² (32.8 )

  = (I₀/2) x 0.706

  = (0.706 / 2 ) x I₀

The light emerging from the third polarizer is represented as,

I₃ = I₂ x cos²θ

Substituting the values in the above equation,

I₃ = ( 0.706 / 2 ) I₀ x cos² (32.8)

  = (0.706 / 2 ) I₀ x 0.706

  = 0.249 I₀

The percentage of intensity of light  that gwts through with respect to the intensity of unpolarized light is given by the equation,

(I₃ / I₀) x 100

Substituting the values

[(0.249 x I₀) / I₀ ] x 100 = 24.9 %

Hence the percentage of light gets through is 24.9%

To learn more about unpolarized light: brainly.com/question/17164167

#SPJ4

6 0
2 years ago
A body has a mass of 2kg.it accelerats from 20m/s to 40m/s in 4 seconds.the resultant force is<br>​
GaryK [48]

The resultant force is 8N  

Given that mass is 2kg , v= 40m/s, u =20m/s and we need to calculate resultant force
F=ma

m is given
so for a
v-u/t=a { first equation of motion }

40-20/4= 4
so a=4

F = ma =2*4 = 8N
The difference between the forces that are acting on an object as part of a system is known as the resultant force.
v = u + at is the first equation of motion. Here, v denotes the end speed, u the starting speed, an acceleration, and t the passage of time. The first equation of motion is provided by the velocity-time relation, which may be used to calculate acceleration.

To learn more about resultant force please visit -
brainly.com/question/22260425
#SPJ1

8 0
2 years ago
The place you get your hair cut has two nearly parallel mirrors 6.5 m apart. As you sit in the chair, your head is
Ghella [55]

Complete question is;

The place you get your hair cut has two nearly parallel mirrors 6.50 m apart. As you sit in the chair, your head is 3.00 m from the nearer mirror. Looking toward this mirror, you first see your face and then, farther away, the back of your head. (The mirrors need to be slightly nonparallel for you to be able to see the back of your head, but you can treat them as parallel in this problem.) How far away does the back of your head appear to be?

Answer:

13 m

Explanation:

We are given;

Distance between two nearly parallel mirrors; d = 6.5 m

Distance between the face and the nearer mirror; x = 3 m

Thus, the distance between the back-head and the mirror = 6.5 - 3 = 3.5m

Now, From the given values above and using the law of reflection, we can find the distance of the first reflection of the back of the head of the person in the rear mirror.

Thus;

Distance of the first reflection of the back of the head in the rear mirror from the object head is;

y' = 2y

y' = 2 × 3.5

y' = 7

The total distance of this image from the front mirror would be calculated as;

z = y' + x

z = 7 + 3

z = 10

Finally, the second reflection of this image will be 10 meters inside in the front mirror.

Thus, the total distance of the image of the back of the head in the front mirror from the person will be:

T.D = x + z

T.D = 3 + 10

T.D = 13m

8 0
3 years ago
Work of 2 joules is done in stretching a spring from its natural length to 11 cm beyond its natural length. what is the force (i
Sidana [21]
The law applied here is Hooke's Law which describes the force exerted by the spring with a given distance. The equation for this is F = kΔx, where F is the force in Newtons, k is the spring constant in N/m while Δx is the displacement in meters.

If you want to find work done by a spring, this can be solved by using differential equations. However, derived equations are already ready for use. The equation is

W = k[{x₂-x₁)² - (x₁-xn)²],

where 
xn is the natural length
x₁ is the stretched length 
x₂ is also the stretched length when stretched even further than x₁

In this case xn =x₁. So, that means that (x₁-xn) = 0 and (x₂-x₁) = 11 cm or 0.11 m.

Then, substituting the values,

2 J = k (0.11² -0²)
k = 165.29 N/m

Finally, we use the value of k to the Hooke's Law to determine the Force.

F = kΔx = (165.29 N/m)(0.11 m)
F = 18.18 Newtons
5 0
4 years ago
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