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Gennadij [26K]
4 years ago
14

If a subway train is moving to the left (has a negative velocity) and then comes to a stop, what is the direction of its acceler

ation? Is the acceleration positive or negative?
Physics
1 answer:
Katen [24]4 years ago
8 0

Answer:

The acceleration would be positive, pointing to the right.

Explanation:

The acceleration tells us how velocity changes every second. If the train stops, this means its velocity must go from a non-zero value to zero.

To reduce velocity, acceleration must point to the opposite direction. Since velocity is negative, acceleration must be positive.

You might be interested in
B
SVEN [57.7K]

Answer:

Frequency = 1,550Hz

Explanation:

To solve this we can use the equation: f=\frac{v}{\lambda}

(frequency = velocity/wavelength).

We are given the information that the wavelength is 22cm and the speed is 340m/s. The first step is to make sure everything is in the correct units (SI units), and to convert them if needed. The SI Units for velocity and wavelength are m/s and m respectively. This means we need to convert 22cm into meters, which we can do by dividing by 100, (as there are 100cm in a meter). 22/100 = 0.22m

Now we can substitute these values into the formula and calculate to solve:

f=\frac{340}{0.22} \\\\f=1545.454...

Simplify to 3 significant figures:

f = 1,550Hz

(Which I believe is just below a G6 if you were interested)

Hope this helped!

4 0
3 years ago
A sports car is advertised to be able to stop in a distance of 50.0 m from a speed of 80 km. What is its acceleration and how ma
Flauer [41]

Explanation:

Given that,

Initial speed of the sports car, u = 80 km/h = 22.22 m/s

Final speed of the runner, v = 0

Distance covered by the sports car, d = 80 km = 80000 m

Let a is the acceleration of the sports car.  It can be calculated using third equation of motion as :

v^2-u^2=2ad

a=\dfrac{v^2-u^2}{2d}

a=\dfrac{0-(22.22)^2}{2\times 80000}

a=-0.00308\ m/s^2

Value of g, g=9.8\ m/s^2

a=\dfrac{-0.00308}{9.8}\ m/s^2

a=(-0.000314)\ g\ m/s^2

Hence, this is required solution.

8 0
3 years ago
when astronauts work in space, they are sometimes attached to the spacecraft by a line called an umbilical. Why do you think the
wariber [46]
Probably for the umbilical cord that connects babies (from their early stages in the womb to their removal) to their mothers. The cord is cut, forming the belly button. This is analogous to astronauts in space.
3 0
4 years ago
Read 2 more answers
How does the cell membrane work to protect the cell?
LenKa [72]
It forms a protective and adaptive barrier around a cell and this keeps various bacterial and viral intruders out. They also help in keeping cell systems inside the cell. The shell absorbs viruses and bacteria for nutrients when they do not have a certain strand to get inside the cell or trick it otherwise. Hope this helped!
3 0
3 years ago
Read 2 more answers
PLEASE ANSWER QUICK :) -
vekshin1

Answer:

At a convergent boundary where both plates are continental, mountain ranges grow and earthquakes are common. At a transform boundary, there is a transform fault and massive earthquakes occur but there are no volcanoes. Processes acting over long periods of time create Earth's geographic features.

Explanation:

4 0
3 years ago
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