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3 years ago

8

A certain car battery with a 12.0 V emf has an initial charge of 131 A · h. Assuming that the potential across the terminals sta

ys constant until the battery is completely discharged, for how many hours can it deliver energy at the rate of 130 W?

1 answer:

irga5000 [103]3 years ago

7 0

Answer:

The battery can supply 130 W for 11.75 h

Explanation:

In order to discover the time in wich the battery can supply this energy we need to find how much current is being drawn from it, we do that by using the equation for real power that is P = V*I, since we have V and P we can solve for I as seen bellow:

I = P/V = 130/12 = 10.834 A

We can use this value to find how many hours the power can supply said current. We do that by dividing the current capacity of the battery by the current drawn:

t = 141/12 = 11.75 h

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A 0.10-kilogram piece of modeling clay is tossed

viva [34]

a) The initial speed of the clay is 30 m/s

b) The final velocity of the block increases (40 m/s)

Explanation:

a)

We can solve this problem by using the law of conservation of momentum. In fact, in absence of external forces (=no friction), the total momentum of the clay + block system is conserved before and after the collision. Therefore, we can write:

$p_i = p_f\\m_1 u_1 + m_2 u_2 = (m_1+m_2)v$

where:

$m_1 = 0.10 kg$ is the mass of the clay

$u_1$ is the initial velocity of the clay

$m_2 = 0.10 kg$ is the mass of the wood block

$u_2 = 0$ is the initial velocity of the wood block (at rest)

$v = 15 m/s$ is the final combined velocity of the clay+block after the collision

Re-arranging the equation, we can find $u_1$ , the speed at which the clay was tossed:

$u_1 = \frac{(m_1+m_2)v-m_2 u_2}{m_1}=\frac{(0.10+0.10)(15)-0}{0.10}=30 m/s$

b)

In this second case, the clay is replaced by a bouncy ball, which rebounds back after the collision, instead of sticking with the block.

In this second case, the law of conservation of momentum becomes:

$p_i = p_f\\m_1 u_1 + m_2 u_2 = m_1 v_1 + m_2 v_2$

where

$m_1 = 0.10 kg$ is the mass of the ball

$u_1 = 30 m/s$ is the initial velocity of the ball

$m_2 = 0.10 kg$ is the mass of the wood block

$u_2 = 0$ is the initial velocity of the wood block (at rest)

$v_1 = -10 m/s$ is the velocity of the bouncing ball after the collision (negative because it goes backward)

$v_2$ is the velocity of the block after the collision

Solving for $v_2$ , we find the final velocity of the block:

$v_2 = \frac{m_1 u_1 - m_1 v_1}{m_2}=\frac{(0.10)(30)-(0.10)(-10)}{0.10}=40 m/s$

As we can see, the final velocity of the block has increased. The reason for that is that, as the ball bounces back, part of the total momentum is "carried away" by the ball in the backward direction, and since the total momentum must remain constant, this means that the momentum carried by the block in the forward direction must be larger than the previous situation.

Learn more about conservation of momentum:

brainly.com/question/7973509

brainly.com/question/6573742

brainly.com/question/2370982

brainly.com/question/9484203

#LearnwithBrainly

7 0

4 years ago

A snowball starting at rest rolls down a hill and reaches 5 m/s. If the hill is

Lostsunrise [7]

Answer:

The acceleration of the snowball is 0.3125

Explanation:

The initial speed of the snowball up the hill, u = 0

The speed the snowball reaches, v = 5 m/s

The length of the hill, s = 40 m

The equation of motion of the snowball given the above parameters is therefore;

v² = u² + 2·a·s

Where;

a = The acceleration of the snowball

Plugging in the values, we have;

5² = 0² + 2 × a × 40

∴ 2 × 40 × a = 5² = 25

80 × a = 25

a = 25/80 = 5/16

a = The acceleration of the snowball = 5/16 m/s².

The acceleration of the snowball = 5/16 m/s² = 0.3125 m/s² .

4 0

3 years ago

What types of alternative fuels did bp pursue after browne became ceo in 1995?

Sliva [168]

Answer:solar energy

Explanation:

This is the energy gotten from sunlight to knock off electrons from fee atom.

This panel contains photovoltaic cells

8 0

3 years ago

What document did the King of England sign that said the people had rights and that the king was not above the law?

Alika [10]

The Magna Carta
Hope it helps!

6 0

3 years ago

In a physics lab, light with a wavelength of 530 nm travels in air from a laser to a photocell in a time of 16.7 ns . When a sla

Harlamova29_29 [7]

Answer:

$\lambda'=78.086\ nm$

Explanation:

Given:

wavelength of light in the air, $\lambda=530\times 10^{-9}\ m$

time taken to travel from the source to the photocell via air, $t=16.7\ s$

time taken to reach the photocell via air and glass slab, $t'=21.3\times 10^{-9}\ s$

thickness of the glass slab, $x=0.87\ m$

<u>Now we have the relation for time:</u>

$\rm time=\frac{distance}{speed}$

hence,

$t=\frac{d}{c}$

c= speed of light in air

$16.7\times 10^{-9}=\frac{d}{3\times 10^8}$

$d=16.7\times 10^{-9}\times 3\times 10^8$

$d=5.01\ m$

For the case when glass slab is inserted between the path of light:

$\frac{(d-x)}{c} +\frac{x}{v} =t'$ (since light travel with the speed c only in the air)

here:

v = speed of light in the glass

$\frac{(5.01-0.87)}{3\times 10^8} +\frac{0.87}{v} =21.3\times 10^{-9}$

$v=4.42\times 10^7\ m.s^{-1}$

Using Snell's law:

$\frac{\lambda}{\lambda'} =\frac{c}{v}$

$\frac{530}{\lambda'} =\frac{3\times 10^8}{4.42\times 10^7}$

$\lambda'=78.086\ nm$

5 0

3 years ago