the number of neutrons may b 21
To solve this exercise we will use the concept related to heat loss which is mathematically given as

Where,
m = mass
= Specific Heat
Change in temperature
Replacing with our values we have that

Specific heat of mercury

Replacing

Therefore the heat lost by mercury is 0.09J
<span>Radius distance from origin to particle = √ (2²+1²) = √5 m = R
I = MR² = (0.200)(5) = 1.00 kg-m²
Θ = arctan 2/1 = 63.4° = R's angle CCW from horizontal
V = 3.0 m/s
V component that is at 90° to R = 3.0(sin 90°- 63.4°) = 3.0(sin 26.6°) = 1.3433 m/s
w = [V component / R] = 1.3433/√5 = 0.601 rad/s
size of angular momentum of particle relative to origin = Iw = (1.00)(0.601) = 0.601 kgm²/s</span><span>
i hope I'm right</span>