Answer:

Explanation:
As we know that train is initially moving with the speed

now we know that

now the final speed of the train when it crossed the crossing


now we can use kinematics here



Now the time to cross that junction is given as



During an exothermic reaction; light and heat are released into the environment.
An exothermic reaction is one in which heat is released to the environment. This heat can be physically observed sometimes like in an a combustion reaction.
In an exothermic reaction, the enthalpy of the reactants is greater than the enthalpy of the products.
This heat lost is sometimes felt as the hotness of the vessel in which the reaction has taken place.
In conclusion, light and heat are released into the environment in an exothermic reaction.
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Answer:
Shown by explanation;
Explanation:
The heat of the sample = mass ×specific heat capacity of the sample × temperature change(∆T)
Assumption;I assume the mass of the samples are : 109g and 192g
∆T= 30.1-21=8.9°c.
The heat of the samples are for 109g are:
0.109 × 4186 × 8.9 =4060.84J
For 0.192g are;
∆T= 67-30.1-=36.9°c
0.192 × 4186×36.9=29656.97J
Answer:
1700 Joules
Explanation:
Work=force x distance
Force = 170 kg
Distance= 10 Meters
170 x 10 = 1700 Joules of work