Answer:
16.33°C
Explanation:
Applying,
Heat lost by copper = heat gained by water
cm(t₁-t₃) = c'm'(t₃-t₂).............. Equation 1
Where c = specific heat capacity of copper, m = mass of copper, c' = specific heat capacity of water, m' = mass of water, t₁ = initial temperature of copper, t₂ = initial temperature of water, t₃ = final equilibrium temperature.
From the question,
Given: m = 50 kg, t₁ = 140°C, m' = 90 L = 90 kg, t₂ = 10°C
Constant: c = 385 J/kg°C, c' = 4200J/kg°C
Substitute these values into equation 1
50(385)(140-t₃) = 90(4200)(t₃-10)
(140-t₃) = 378000(t₃-10)/19250
(140-t₃) = 19.64(t₃-10)
140-t₃ = 19.64t₃-196.6
19.64t₃+t₃ = 196.4+140
20.64t₃ = 336,4
t₃ = 336.4/20.6
t₃ = 16.33°C
Answer:
The given statement is false.
Explanation:
For any negative vector
The magnitude of the vector is given by
As we know that square root of any quantity cannot be negative thus we conclude that the right hand term in the above expression cannot be negative hence we conclude that magnitude of any vector cannot be negative.
Answer:
-50 N
Explanation:
Givens:
V_i = 36 km/h
V_f = 18 km/h
t = 2 s
m = 20 kg
First we have to convert our km/h into m/s:
(36 km*(1000 m/1 km)) / (60 min *(60 s/1 min)) = 10 m/s
(18 km*(1000 m/1 km)) / (60 min *(60 s/1 min)) = 5 m/s
a = (V_f - V_i)/t
a = (5 m/s - 10 m/s) / 2 s
a = -2.5 m/s^2
F = m(a)
F = 20 kg(-2.5 m/s^2)
F = -50 N
It's a negative force meaning its acting on it opposite its current direction of movement.
