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atroni [7]
3 years ago
10

A truck covers 40.0 m in 7.10 s while smoothly slowing down to a final velocity of 2.75 m/s.. (a) Find the truck's original spee

d.
Physics
1 answer:
ser-zykov [4K]3 years ago
4 0
D = vo t - at²/2
v = vo - at
40 m = vo · 7.10 - a · ( 7.10 )²/2
40 m = 7.10 vo - a· 50.41/2
40 m = 7.10 vo - 25.205 a
2.75 m/s = vo - 7.10 a   ⇒  a = ( vo - 2.75 )/ 7.10
40 = 7.10 vo - 25.205 · ( vo - 2.75 ) / 7.10
40 = 7.1 vo - 3.55 vo + 9.7625
3.55 vo = 30.2375 
vo = 30.2375 : 3.55 = 8.5176 m/s
Answer: the truck`s original speed is 8.5176 m/s.
 
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Answer:

t = 0.0735 m

Explanation:

Angular acceleration of the flywheel is given as

\alpha = 3 rad/s^2

now after t = 8 s the speed of the flywheel is given as

\omega = \alpha t

\omega = 3 \times 8

\omega = 24 rad/s

now rotational kinetic energy of the wheel is given as

K = \frac{1}{2}I\omega^2

K = \frac{1}{2}(\frac{1}{2}mR^2)(24^2)

800 = \frac{1}{4}m(0.23)^2(24^2)

m = 105 kg

now we have

m = \rho (\pi R^2) t

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4 0
3 years ago
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navik [9.2K]

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6 0
3 years ago
The two forces acting on a skydiver are __________ and air _____________.
Stolb23 [73]

Answer:

Gravity and

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Explanation:

The two forces acting on a skydiver are gravitational force and air resistance.

Gravitational force is a force that tends to pull all massive bodies towards the center of the earth. It works on all bodies that has mass. The larger or bigger the mass, the more the pull of gravity on the body.

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3 0
3 years ago
Read 2 more answers
Hello,help me with this out please i need it hurry but please ensure your answer is correct..I attach here with my question.
lilavasa [31]

Answer:

.409 N

Explanation:

For this to balance, the moments around the fulcrum must sum to zero.

On the left you have   .21   ( is that down? I will assume it is)

      Counterclockwise moments :

        .21 * 40     +  1.0 * 20    

     Clockwise moments :

        .5 * 20     +     F * 45

these moments must equal each other

.21*40 + 1 *20   =  .5 * 20 + F * 45

   F = .409 N

7 0
2 years ago
What is the conclusion of coin and feather experiment? ​
valina [46]

Answer:

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5 0
3 years ago
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