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2 years ago

(i) 10 m (ii) 20 m (iii) 40 m (iv) 80 m

Physics

1 answer:

IRINA_888 [86]2 years ago

6 0

Answer:

20m

420=80m

100

increases

increases then decreases

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A ball rolls down the hill which has a vertical height of 15 m. Ignoring friction what would be the gravitational potential ener

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a) Potential energy: 147 m [J]

The gravitational potential energy of an object is given by

$U=mgh$

where

m is its mass

$g=9.8 m/s^2$ is the acceleration of gravity

h is the height of the object above the ground

In this problem,

h = 15 m

We call 'm' the mass of the ball, since we don't know it

So, the potential energy of the ball at the top of the hill is

$U=(m)(9.8)(15)=147 m$ (J)

b) Velocity of the ball at the bottom of the hill: 17.1 m/s

According to the law of conservation of energy, in absence of friction all the potential energy of the ball is converted into kinetic energy as the ball reaches the bottom of the hill. Therefore we can write:

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We know from part a) that

U = 147 m

Substituting into the equation above,

$147 m = \frac{1}{2}mv^2$

And re-arranging for v, we find the velocity:

$v=\sqrt{2\cdot 147}=17.1 m/s$

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With the switch open, roughly what must be the resistance of the resistor on the right for the current out of the battery to be

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Answer:

The resistance must be 6.67 $\Omega$

Solution:

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Resistance, $R_{2} = 10\Omega$

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Thus in parallel:

$\frac{1}{R_{eq}} = \frac{1}{R_{1}} + \frac{1}{R_{2}}$

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Answer:

Explanation:

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From the question

mass = 7 kg

acceleration = 6 m/s²

We have

force = 7 × 6 = 42

We have the final answer as

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