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3 years ago

If a boat and its riders have a mass of 900 kg and the boat drifts in at 1.4 m/s how much work does sam do to stop it?

1 answer:

6 0

The initial kinetic energy of the boat and its rider is
$K_i = \frac{1}{2} mv_i^2 = \frac{1}{2}(900 kg)(1.4 m/s)^2=882 J$

After Sam stops it, the final kinetic energy of the boat+rider is
$K_f = 0 J$
because its final velocity is zero.

For the law of conservation of energy, the work done by Sam is the variation of kinetic energy of the system:
$W=K_f-K_i =0-882 J=-882 J$
where the negative sign is due to the fact that the force Sam is applying goes against the direction of motion of the boat.

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A solar panel measures 0.57 m by 1.3 m. In direct sunlight, the panel delivers 6.6 A at 6 V. If the intensity of sunlight is 300

zheka24 [161]

Answer:

efficiency of solar panel is 18%

Explanation:

Energy received by the sunlight is given as

$Power = intensity \times area$

here we know the dimensions of the plate as

$L = 0.57 m$

$W = 1.3 m$

now we have

$Area = (0.57)(1.3) m^2$

$A = 0.741 m^2$

now the power received by the sun light is given as

$P_1 = 0.741(300) = 222.3 W$

now the output power due to solar panel is given as

$P_{out} = V i$

$P_{out} = (6.6 A)(6 V)$

$P_{out} = 39.6 Watt$

now the efficiency is given as

$\eta = \frac{P_{out}}{P_{in}}$

$\eta = \frac{39.6}{222.3}$

$\eta = 0.18$

8 0

3 years ago

Write a simple rule that will tell a person how many water molecule will be lost while putting monosaccharides together to form

belka [17]

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2 years ago

What is the element with the lowest electronegativity value?

Lerok [7]

<h2>Answer: Francium </h2>

Let's start by explaining that electronegativity is a term coined by Linus Pauling and is determined by the <em>ability of an atom of a certain element to attract electrons when chemically combined with another atom. </em>

So, the more electronegative an element is, the more electrons it will attract.

It should be noted that this value can not be measured directly by experiments, but it can be determined indirectly by means of calculations from other atomic or molecular properties of the element. That is why the scale created by Pauling is an arbitrary scale, where the maximum value of electronegativity is 4, assigned to Fluorine (F) and the <u>lowest is 0.7, assigned to Francium (Fr).</u>

7 0

3 years ago

A ball is dropped from rest at the top of a 6.10 m

natita [175]

Answer:

n = 5 approx

Explanation:

If v be the velocity before the contact with the ground and v₁ be the velocity of bouncing back

$\frac{v_1}{v}$ = e ( coefficient of restitution ) = $\frac{1}{\sqrt{10} }$