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Marina86 [1]
3 years ago
13

A 2 kg object is released from rest from a height of 3 m above Earth's surface. How much kinetic energy does the object have whe

n it reaches a height of 1 m? (A) 2.5 J (B) 10 J (C) 20 J (D) 30 J (E) 40 JFigure:A 2kg object is hanging
Physics
1 answer:
borishaifa [10]3 years ago
4 0

Answer:

Kinetic energy, E = 40 Joules

Explanation:

Given that,

Mass of the object, m = 2 kg

It is released from rest from a height of 3 m above Earth's surface, h_1=3\ m

We need to find the kinetic energy the object have when it reaches a height of 1 m, h_2=1\ m

It is a case of conservation of mechanical energy. It states that the total energy of the system remains constant. The kinetic energy is given by :

E=mg(h_1-h_2)

E=2\times 10\times (3-1)

E = 40 Joules

So, the kinetic energy of the object when it reaches a height of 1 m is 40 joules. Hence, this is the required solution.

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r2 = 2.401557  cm

distance = 0.10 cm

Explanation:

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solution

we know here potential difference that is express as

ΔV = \frac{\lambda }{2\pi \epsilon _o} ln\frac{r2}{r1}     ...........1

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ln\frac{r2}{r1} = 2\pi \epsilon _o \times \frac{\triangle V}{\lambda }  

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\frac{r2}{r1} = e^{2\pi \epsilon _o \times \frac{\triangle V}{\lambda }}  

r2 = r1 × e^{2\pi \epsilon _o \times \frac{\triangle V}{\lambda }}  

r2 = 2.40 × e^{2\pi 8.85\times 10^{-12} \times \frac{175}{15\times 10^{-6} }}  

r2 = 2.401557  cm

and

here distance above surface will be

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distance = 0.10 cm

4 0
3 years ago
A horizontal disk with a radius of 23 m rotates about a vertical axis through its center. The disk starts from rest and has a co
lys-0071 [83]

Answer:

time is 0.42 sec

Explanation:

Given data

radius = 23 m

angular acceleration = 5.7 rad/s²

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time

solution

we know that radius is constant so that

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tangential acceleration =  5.7 × 23 = 131.1 m/s²

and

radial acceleration Ar =  (angular velocity)² × radius    ........................2

we consider angular velocity = ω

this is acting toward center

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compare 1 and 2

At = Ar

5.7 r =ω³ r

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ω = 5.7 t

2.387 = 5.7 t

t =  2.387 / 5.7

t = 0.4187

time is 0.42 sec

8 0
3 years ago
Answer the question below
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You are out and about in the country and your father sees a rock that he really wants in the yard. Now you must get the very hea
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3 years ago
I am sitting on a train car traveling horizontally at a constant speed of 50 m/s. I throw a ball straight up into the air.
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Answer:

Explanation:

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As soon as ball is separated from the hand , it acquires addition velocity in upward direction and acceleration in downward direction . This will give relative velocity to the ball with respect to me . So I will see the ball going in upward direction under  gravitational acceleration . It appears as if I am sitting at rest and ball is going in upward direction under deceleration . My motion at 50 m/s will have no effect on the motion of ball in upward direction , according to first law of Newton . It is so because ball too will be moving in forward direction with the same speed which will not be visible to me because I too am moving with the same speed.

If I  am  sitting at rest at home and I threw a ball straight up into the air , I will have the same experience of seeing ball going in similar way as described above.

8 0
3 years ago
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