D. Acts at a distance, because magnetic forcefield is in two dots, Earth's north and south magnetic poles, and magnet is on some distance from them.
Given:
m₁ = 1540 g, mass of iron horseshoe
T₁ = 1445 °C, initial temperature of horseshoe
c₁ = 0.4494 J/(g-°C), specific heat
m₂ = 4280 g, mass of water
T₂ = 23.1 C, initial temperature of water
c₂ = 4.18 J/(g-°C), specific heat of water
L = 947,000 J heat absorbed by the water.
Let the final temperature be T °C.
For energy balance,
m₁c₁(T₁ - T) = m₂c₂(T - T₂) + L
(1540 g)*(0.4494 J/(g-C))*(1445-T C) = (4280 g)*(4.18 J/(g-C))*(T-23.1 C) + 947000 J
692.076(1445 - T) = 17890(T - 23.1) + 947000
10⁶ - 692.076T = 17890T - 413259 + 947000
466259 = 18582.076T
T = 25.09 °C
Answer: 25.1 °C
Divide 400/200 and that should give you your answer
A) Vt = Vo - gt
= 0 - 9.8 . 2
= - 19.6 m/sec (acting downward)
b) ∆y = Vt^2 - Vo^2 / 2g
= (-19.6)^2 - 0 / 19.6 = 19.6 meters