Answer:
300 m
Explanation:
The train accelerate from the rest so u = 0 m/sec
Final speed that is v = 80 m/sec
Time t = 30 sec
The distance traveled by first plane = 1200 m
We know the equation of motion
where s is distance a is acceleration and u is initial velocity
Using this equation for first plane 

As the acceleration is same for both the plane so a for second plane will be 2.67 
The another equation of motion is
using this equation for second plane 
s = 300 m
Answer:
An electric field is a region around a charged object where the object's electric force is exerted on other charged objects. Electric fields get weaker the farther away they are from the charge. An electric field is invisible. You can use the field line to represent it.
Explanation:
Answer:
0.9 N
Explanation:
The force exerted on an object is related to its change in momentum by:

where
F is the force exerted
is the change in momentum
is the time interval
The change in momentum can be rewritten as

where
m is the mass
u is the initial velocity
v is the final velocity
So the formula can be rewritten as

In this problem we have:
is the mass rate
is the initial velocity
is the final velocity
Therefore, the force exerted by the hail on the roof is:

for acceleration we can define that rate of change in velocity is know as acceleration
So whenever velocity of train is changing with time we can say train is accelerating
Now here if initially train is standstill then after some time its speed is 5 m/s
so here the train is accelerated first time
Then on straight path its speed changed from 5 m/s to 10 m/s so here train gets accelerated second time
After this train chugged around a curve with same speed 10 m/s
SO here since train is moving in curve so here its direction of velocity is continuously changing and this type of acceleration is known as centripetal acceleration
SO this is accelerated Third time
Then its speed decreases and it comes to speed of 5 m/s from 10 m/s
So here it is acceleration of train for Fourth time
Then finally train comes to stop so again its speed changed from 5 m/s to 0
so this is acceleration of train Fifth time
So total train will accelerate 5 times in whole path