2 years ago

About when was the sail developed, making travel possible on the open water?

Physics

1 answer:

dalvyx [7]2 years ago

4 0

The first sail was developed in 1300 BC in Mesopotamia

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Two groups of students were tested to compare their speed working math problems,Each group was given the same problems.One group

Zanzabum

Your hypothesis can be that the group with calculators would finish faster than the group without calculators.

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3 years ago

19. After a snowstorm, you put on your frictionless skis and tie a rope to the back of your friend’s truck. Your total mass is 7

Kisachek [45]

Explanation:

It is given that,

Total mass is 70 kg

The truck exerts a constant force of 20 N.

Then the net force is given by :

F = ma

a is acceleration of rider

$a=\dfrac{F}{m}\\\\a=\dfrac{20}{70}\\\\a=\dfrac{2}{7}\ m/s^2$

Initial velocity of rider is 0. So, using equation of kinematics to find the final velocity as :

$v=u+at\\\\v=at\\\\v=\dfrac{2}{7}\times 15\\\\v=4.28\ m/s$

Since, 1 m/s = 2.23 mph

4.28 m/s = 9.57 mph

So, the speed of the rider is 4.28 m/s or 9.57 mph.

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2 years ago

A body of mass 3.0Kg is acted upon by a force of 24N, if the frictional force on the body is 13N.Calculate the acceleration of t

lisabon 2012 [21]

Answer:

Fnet=ma

24-13=3a

11/3=a

a=3.6m/s2

4 0

2 years ago

How many valence electrons do most stable atoms have?

IceJOKER [234]

Answer:

D) 8

Explanation:

Due to the octet rule the most stable atoms will have 8 valence electrons.

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2 years ago

A far-sighted person has a near-point of 80 cm. To correct their vision so that they can see objects that are as close as 10 cm

bekas [8.4K]

Answer:

$f = 8.89 cm$

Explanation:

As we know that Far sighted person has near point shifted to 80 cm distance

so he is able to see the object 80 cm

now the distance of lens from eye is 2 cm

and the person want to see the objects at distance 10 cm

so here the image distance from lens is 80 cm and the object distance from lens is 8 cm

now from lens formula we have

$\frac{1}{d_i} + \frac{1}{d_0} = \frac{1}{f}$

$-\frac{1}{80} + \frac{1}{8} = \frac{1}{f}$

$f = 8.89 cm$

3 0

3 years ago