In which direction will the object accelerate?

Two subway stops are separated by 1210 m. If a subway train accelerates at 1.30 m/s2 from rest through the first half of the dis

solong [7]

Answer:

Part 1) Time of travel equals 61 seconds

Part 2) Maximum speed equals 39.66 m/s.

Explanation:

The final speed of the train when it completes half of it's journey is given by third equation of kinematics as

$v^{2}=u^2+2as$

where

'v' is the final speed

'u' is initial speed

'a' is acceleration of the body

's' is the distance covered

Applying the given values we get

$v^2=0+2\times 1.30\times \frac{1210}{2}\\\\v^{2}=1573\\\\\therefore v=39.66m/s$

Now the time taken to attain the above velocity can be calculated by the first equation of kinematics as

$v=u+at\\\\v=0+1.30\times t\\\\\therefore t=\frac{39.66}{1.30}=30.51seconds$

Since the deceleration is same as acceleration hence the time to stop in the same distance shall be equal to the time taken to accelerate the first half of distance

Thus total time of journey equals $T=2\times 30.51\approx61seconds$

Part b)

the maximum speed is reached at the point when the train ends it's acceleration thus the maximum speed reached by the train equals $39.66m/s$

4 0

3 years ago

What is work - energy theorem ??

Elden [556K]

The work-energy theorem explains the idea that the net work - the total work done by all the forces combined - done on an object is equal to the change in the kinetic energy of the object. After the net force is removed (no more work is being done) the object's total energy is altered as a result of the work that was done.

This idea is expressed in the following equation:

is the total work done

is the change in kinetic energy

is the final kinetic energy

is the initial kinetic energy

mark me as brainliest ❤️

3 0

3 years ago

Read 2 more answers

What are some indicators that a chemical reaction is occurring? Check all that apply.

VikaD [51]

Hi there! When a chemical Reaction happens, the tell tale signs are as listed:
~The chemical produces bubbles
~ The Chemical emits an odor
~ The liquid forms a solid(Precipitate)
~ There is a change of color
~ And last but not least a change in temperature!

Hope this can help! Good luck!

6 0

3 years ago

Read 2 more answers

Children in a tree house lift a small dog in a basket 4.00 m up to their house. If it takes 187 J of work to do this, what is th

Vika [28.1K]

A=Fh
A - work
F - force
h - distance

F=mg
m - mass (god+basket)

so
A=mgh
187 = m*10*4
187=40m
m=187/40
m=4.675 kg
or 4kg and 675g

pretty small dog...

6 0

3 years ago

Define the physics quantity of work

umka2103 [35]

Explanation:

Work done is the force applied to move a body through a specific or particular direction.

It is also the difference in the amount of energy expended in using an effort.

Work done is given as;

Work done = F x d CosФ

F is the force applied

d is the displacement

Ф is the angle

The unit of work done is in Joules.

5 0

3 years ago