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Thepotemich [5.8K]

2 years ago

11

Eight books, each 4.6 cm thick and of mass 1.8 kg, lie on a flat table. How much work work is required to stack them on top of o

ne another?

1 answer:

pantera1 [17]2 years ago

3 0

Answer:

529.92Newton Meters

Explanation:

Work=force x displacement

8books in total

force is 1.8kg

dispplacement is 4.6cm

times both units by 8 and u get

force - 14,4

displacement - 36.8

now times boht together and u get 529.92nm

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Novay_Z [31]

Answer:

Explanation:

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3 years ago

| A T-ball with a mass of 0.6 kg travels in the

r-ruslan [8.4K]

Answer:

$|I|=6\ Kg.m/s$

$F=120\ N$

Explanation:

Impulse and Momentum

They are similar concepts since they deal with the dynamics of objects having their status of motion changed by the sudden application of a force. The momentum at a given initial time is computed as

$p_o=m.v_o$

When a force is applied, the speed changes to $v_1$ and the new momentum is

$p_1=m.v_1$

The change of momentum is

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The impulse is equal to the change of momentum of an object and it's defined as the average net force applied times the time it takes to change the object's motion

$I=F.t=\Delta p$

Part 1

The T-ball initially travels at 10 m/s and then suddenly it's stopped by the glove. The final speed is zero, so

$\Delta p=0.6\ Kg(0-10\ m/s)=-6\ Kg.m/s$

The impulse is

$I=\Delta p$

$I=-6\ Kg.m/s$

The magnitude is

$|I|=6\ Kg.m/s$

Part 2

The force can be computed from the formula

$I=F.t$

The direction of the impulse the T-ball receives is opposite to the direction of the force exerted by the ball on the glove, thus $I_b=6\ kg.m/s$

$\displaystyle F=\frac{I}{t}=\frac{6\ kg.m/s}{0.05\ s}$

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3 years ago

A tennis ball is hit into the air with a racket. When is the ball’s kinetic energy the greatest? Ignore air resistance. when it

natita [175]

<h3><u>Answer;</u></h3>

just before it reaches the ground

<h3><u>Explanation;</u></h3>

Kinetic energy is the energy possessed by a body or an object in motion.
<em><u>Kinetic energy is given by 1/2mv², where m is the mass of the object and V is the velocity of the body. Thus, kinetic energy depends on the velocity of the body if mass is kept constant.</u></em>
<em><u>As soon as the ball leaves the racket it has more kinetic energy and zero potential energy. As it moves up its velocity decreases, and thus the kinetic energy is being converted to kinetic energy up to maximum height reached where kinetic energy will be zero since the velocity is zero.</u></em>
<em><u>When the ball is going down the potential energy will be converted to kinetic energy up to a point just before it hits the ground, where kinetic energy is maximum since the velocity of the ball is maximum, due to gravitational acceleration.</u></em>

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3 years ago

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How do astronomers use parallax to calculate a stars distance?

Maslowich

Astronomers can measure a star's<span> position once, and then again 6 months later and </span>calculate<span> the apparent change in position. The </span>star's<span> apparent motion is called stellar </span>parallax<span>. The </span>distance<span> d is measured in parsecs and the </span>parallax<span> angle p is measured in arc seconds.</span>

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3 years ago

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What area must the plates of a capacitor be if they have a charge of 5.7uC and an electric field of 3.1 kV/mm between them? O 0.

kirill [66]

Answer:

Area of the plates of a capacitor, A = 0.208 m²

Explanation:

It is given that,

Charge on the parallel plate capacitor, $q = 5.7\ \mu C=5.7\times 10^{-6}\ C$

Electric field, E = 3.1 kV/mm = 3100000 V/m

The electric field of a parallel plates capacitor is given by :

$E=\dfrac{q}{A\epsilon_o}$

$A=\dfrac{q}{E\epsilon_o}$

$A=\dfrac{5.7\times 10^{-6}\ C}{3100000\ V/m\times 8.85\times 10^{-12}\ F/m}$

A = 0.208 m²

So, the area of the plates of a capacitor is 0.208 m². Hence, this is the required solution.

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3 years ago