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yan [13]
1 year ago
10

a person of mass 70 kg is standing in an elevator that is moving downward. the speed decreases uniformly from 4.0 m/s to zero in

2.0 s. what is the normal force acting on the person?
Physics
1 answer:
Anuta_ua [19.1K]1 year ago
6 0

The normal reaction of the boy of mass 70 kg is 826 N.

Let us understand about normal reaction.

The force exerted by a surface on an object in contact with it which prevents the object from passing through the surface is called Normal reaction.

To calculate the normal reaction, we use the formula below.

Formula:

N = mg+m(v-u)/t.......... Equation 1

Where:

N = Normal reaction

m = Mass of the person

g = Acceleration due to gravity

v = Final Velocity

u = Initial velocity

t = Time

From the question,

Given:

m = 70 kg

v = 4 m/s

u = 0 m/s

t = 2 s

g = 9.8 m/s²

Substitute these values into equation 1

N = (70×9.8)+70(4-0)/2

N = 686+140

N = 826 N

Hence, the normal reaction of the boy is 826 N.

Learn more about normal reaction here: brainly.com/question/28788588

#SPJ4

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Answer

given,

initial speed of merry-go-round = 0 rad/s

final speed of merry-go-round = 1.5 rad/s

time = 7 s

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Mass of the merry-go-round = 25000 Kg

Moment of inertia of the disk

I = \dfrac{1}{2}MR^2

I = \dfrac{1}{2}\times 25000\times 6^2

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angular acceleration

\alpha = \dfrac{\omega_f-\omega_0}{t}

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\alpha =0.214\ rad/s^2

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3 years ago
A particle covers 10m distance in 2sec. if final velocity is 8m/s, find initial velocity​
klasskru [66]

Explanation:

It is given that a particle covers 10m in first 5s and 10m in next 3s. so using the equation of motion

Case I

s=ut+

2

1

at

2

10=5u+

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1

a(5)

2

20=10u+25a

4=2u+5a..............(1)

Case 2

In next 3s the particle covers more 10m distance. So

20=8u+

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1

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2

5=2u+8a.........(2)

On solving equation (1) and (2)

4=2u+5a

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a=

3

1

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2

Put the value of a in equation (1)

u=

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7

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Now to find distance in next 10 s. total time will be 10s

s=

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×10+

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×

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