Answer:
2730.304 KJ
Explanation:
How much heat is required to convert 0.8 kg of ice at -35°C into steam at 100 C?
Given that:
mass of ice (m) = 0.8 kg = 800 g
Initial temperature () = -35°C = 238 K
final temperature ()= 100°C = 373 K
Specific heat of ice () = 2.108 J/g.K
Specific heat of water () = 4.18 J/g.K
Latent heat of fusion () = 334 J/g.
Latent heat of vaporization () = 2230 J/g.
Total heat (Q) required to increase the temperature of ice from the initial temperature of 238K to final temperature of 373 K is given by the equation:
Answer: 68.4 s
Explanation:
The plot points seem to indicate a 5 m/s increase in velocity in the 6 seconds between 2 and 8 second marks. This makes the acceleration
a = 5 / 6 m/s/s
At time zero, the velocity is 13 m/s, so we need to increase by
70 - 13 = 57 m/s
t = v/a = 57 / (5/6) = 68.4 s
It's implying that a constant force was applied throughout, which also means that there was a constant, negative acceleration. Because of that, the deceleration is equal to the change in velocity (-24.3 m/s) divided by the time (17.2 s):
=-1.41279 m/s^2. The force is technically negative because it is causing a negative acceleration. Because F=ma: -2170kg m/sec^2=-(-1.41279 m/sec^2)m. m=
=<u>1535.9678 kg</u>
Measuring things lets us understand the world
Answer:
μ = 0.66, therefore if it compiesy with the regulations
Explanation:
Let's solve this exercise in part, let's start by finding with kinematics the acceleration of man
y = v₀ t + ½ a t²
as it starts from rest the initial velocity is zero
y = ½ a t²
a =
a =\frac{2 \ 4.38}{1.21^2}
a = 6.46 m / s²
Now let's use Newton's second law,
Axis y
N- W = 0
N = W
N = m g
X axis
on this axis the man exerts a backward force and by the law of action and reaction the floor exerts a forward force of the same magnitude, this forward force is the friction force.
fr = m a
the friction force has an expression
fr = my N
let's substitute
μ mg = m a
μ = a / g
let's calculate
μ = 6.46 / 9.8
μ = 0.66
therefore if you comply with the regulations