A)
v = 25m/s = 2,5 * 3,6 km/h = 90 km/h
t = 0,5h
s = ?
s = v*t
s = 90km/h * 0,5h = 45m
B)
a = 4m/s²
t = 12,5s
v = ?
v = a * t
v = 4m/s² * 12,5s = 50m/s
C)
m = 2,5kg
F = 12N
a = ?
a = F/m
a = 12N / 2,5kg = 4,8m/s²
D)
p = 3,5 hPa = 350Pa
S = 12m²
F = ?
p = F/S
F = p * S
F = 350Pa * 12m² = 4200N = 4,2kN
E)
d = 800kg/m³
V = 4,5m³
m = ?
d = m/V
m = d *V
m = 800kg/m³ * 4,5m³ = 3600kg = 3,6t
F)
F = 45N
W = 18J
s = ?
W = F * s
s = W / F
s = 18J / 45N = 2/5m = 0,4m
G)
P = 2,1kW = 2100W
t = 12min = 12*60s = 720s
W = ?
P = W /t
W = P * t
W = 2100W *720s = 1512000J = 1512kJ
H)
ΔT = 2°C
Q = 6,4kJ = 6400J
c = 4200 J/kg*°C
m = ?
Q = m * c * ΔT
m = Q / (c * ΔT)
m = 6400J / (4200 J/kg*°C * 2°C) = 0,76kg
