Answer:
v = 25 m / s
Explanation:
For this exercise we use the relations and kinematics
first part, the train accelerates from v₀ = 7.0 m/s to 13 m/s in a time t = 8.0 s
v = v₀ + a t
a =
a =
a = 0.75 m / s²
second part. Accelerate again for t = 16 s
v = v₁ + a t
for this interval the initial velocity is v₁ = 13 m / s
v = 13 + 0.75 16
v = 25 m / s
Answer:
water is in the vapor state,
Explanation:
We must use calorimetry equations to find the final water temperatures. We assume that all energy is transformed into heat
E = Q₁ +
Where Q1 is the heat required to bring water from the current temperature to the boiling point
Q₁ = m (
-T₀)
Q₁ = 50 4180 (100 - 37)
Q₁ = 1.317 10⁷ J
Let's calculate the energy so that all the water changes state
= m L
= 50 2,256 106
= 1,128 10⁸ J
Let's look for the energy needed to convert all the water into steam is
Qt = Q₁ +
Qt = 1.317 107 + 11.28 107
Qt = 12,597 10⁷ J
Let's calculate how much energy is left to heat the water vapor
ΔE = E - Qt
ΔE = 10¹⁰ - 12,597 10⁷
ΔE = 1000 107 - 12,597 107
ΔE = 987.4 10⁷ J
With this energy we heat the steam, clear the final temperature
Q = ΔE = m (
-To)
( -T₀) = ΔE / m
= T₀ + ΔE / m
= 100 + 987.4 10⁷ / (50 1970)
= 100 + 1,002 10⁵
= 1,003 10⁵ ° C
This result indicates that the water is in the vapor state, in realizing at this temperature the water will be dissociated into its hydrogen and oxygen components
Answer:
Planet B
Explanation:
The strength of the gravitational field on the surface of a planet is given by the equation:
(1)
where:
G is the gravitational constant
M is the mass of the planet
R is the radius of the planet
In this problem, we have two planets, A and B.
The two planets have same radius, R, while they have different masses, in particular
So, the mass of planet B is twice the mass of planet A.
Looking at the eq.(1), we see that the gravitational field strength is proportional to the mass of the planet: therefore, the larger the mass, the greater the field strength.
So, since planet B has larger mass, then its gravity will be stronger than planet A.