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3 years ago

An object is thrown straight up into the air at 10 m/s. how fast is the object traveling after 2 seconds?

Physics

1 answer:

ziro4ka [17]3 years ago

7 0

First write down all the known variables:

vi = 10m/s

t = 1

a = -9.8m/s^2

vf = ?

Now choose the kinematic equation to relate these variables:

vf = vi + at

vf = (10) + (-9.8)(1)

vf = 0.2 m/s

The speed of the object travelling after a second would be 0.2m/s in reality, however, it is closest to the choice A, which would suffice as the answer for your question.

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Vector sum of 15 m, East and 9 m, West is 24 m, East. True False

Firlakuza [10]

Answer:

False

Explanation:

Because when you go through east

( +x axis ) then you go to west ( -x axis )

You will subtract -9 from +15

it's become +6

( I talk about the displacement not distance) ( West = - East )

I hope that it's a clear ") .

7 0

3 years ago

Read 2 more answers

In the far future, astronauts travel to the planet Saturn and land on Mimas, one of its 62 moons. Mimas is small compared with t

Mamont248 [21]

Answer:

a) $h_{max}=14536.16 m$

b) $h = 15687.9 m$

c) $PD=7.62\%$ The estimate is low.

Explanation:

a) Using the energy conservation we have:

$E_{initial}=E_{final}$

we have kinetic energy intially and gravitational potential energy at the maximum height.

$\frac{1}{2}mv^{2}=mgh_{max}$

$h_{max}=\frac{v^{2}}{2g}$

$h_{max}=\frac{43^{2}}{2*0.0636}$

$h_{max}=14536.16 m$

b) We can use the equation of the gravitational force

$F=G\frac{mM}{R^{2}}$ (1)

We have that:

$F = ma$ (2)

at the surface G will be:

$G=\frac{gR^{2}}{M}$

Now the equation of an object at a distance x from the surface.

is:

$F=\frac{mgR^{2}}{(R+x)^{2}}$

$m\frac{dv}{dt}=\frac{mgR^{2}}{(R+x)^{2}}$

Using that dv/dt is vdx/dt and integrating in both sides we have:

$v_{0}=\sqrt{\frac{2gRh}{R+h}}$

$h=\frac{v_{0}^{2}R}{2gR-v_{0}^{2}}$

$h=15687.9$

c) The difference is:

So the percent difference will be:

$PD=|\frac{14536.16-15687.9}{(14536.16+15687.9)/2}*100%$

$PD=7.62\%$

The estimate is low.

I hope it helps you!

7 0

3 years ago

Which type of ladder has flat steps, hinged back, self-supporting, and non-adjustable?

il63 [147K]

Answer: Step Ladders

In general ladders are with inclined or vertical set of steps or rungs between two upright lengths of metal or wood. Ladders used for climbing up and down.

<u>Step ladders :</u>

It is a self supporting portable ladder, most commonly used in industries. Self-supporting means it does not need any support to lean. So this ladder can be used any where in the rooms. For example middle of the room where support is not available. Also this ladder is non-adjustable flat steps and hinged back.

5 0

3 years ago

A concave lens has a focal length of -31 {cm}. Find the image distance and magnification that results when an object is placed 2

kolezko [41]

Answer:

The value is $v = 440 \ cm$

and

$m = 16$

Explanation:

From the question we are told that

The image distance is $v = 29 \ cm$

The focal length is $f = -31 \ cm$

From the lens equation we have that

$\frac{1}{f} = \frac{1}{v} - \frac{1}{u}$

=> $\frac{1}{-31} = \frac{1}{v} - \frac{1}{29}$

=> $v = 450 \ cm$

Generally the magnification is

$m = \frac{v}{u}$

=> $m = \frac{ 450}{29}$

=> $m = 16$

7 0

3 years ago

9. You drive a car from Milwaukee to Chicago, which is a distance of 150km and it takes you 95

Katena32 [7]

For this case we have to, by definition:

$v = \frac {x} {t}$

Where:

v: It's the velocity

x: It is the distance traveled

t: It is the time spent

1 hour equals 60 minutes and 1 minute equals 60 seconds.

On the other hand:

1 kilometer equals 1000 meters

So: $\frac {150} {95} \frac{km} {min} * \frac {1} {60} \frac {min} {sec} * \frac {1000} {1} \frac {m} {km} = \frac {150 * 1000} {95 * 60} \frac {m} {sec} = \frac {15000} {5700} \frac {m} {sec} = 2.63 \frac {m} {sec}$

On the other hand: $\frac {150} {95} \frac{km} {min} * \frac {60} {1} \frac {min} {hr} = \frac {150 * 60} {95} \frac {km} {h} = 94.74 \frac {km} {h}$

ANswer:

$2.63 \frac {m} {sec}\\94.74 \frac {km} {h}$

8 0

3 years ago