By the law of momentum conservation:-
=>m¹u¹ + m²u² = m1v1 + m²v² {let East is +ve}
=>u¹ + u² = v¹ + v² {as m1=m2}
=>3.5 - 2.75 = v1-1.5
<span>
=>v¹ = 2.25 m/s (East) </span>
Answer:

Explanation:
First of all let's define the specific molar heat capacity.
(1)
Where:
Q is the released heat by the system
n is the number of moles
ΔT is the difference of temperature of the system
Now, we can find n with the molar mass (M) the mass of the compound (m).
Using (1) we have:


I hope it helps!
I think your answer would be DDT, but don't hold me to it
No, one more group must get the same result as the other group. This will make it more reliable and reproducible.