Answer:
884 m
Explanation:
The motion of the baseball is a projectile motion: a uniform motion along the horizontal direction and a uniformly accelerated motion along the vertical direction.
The horizontal range of a projectile (the horizontal distance covered by the object before it reaches the original vertical height) is given by
where
u is the initial speed
is the angle of launch
g = 9.8 m/s^2 is the acceleration of gravity
For the ball in this problem,
u = 100 m/s
Substituting into the equation, we find the range of the ball:
so, the ball will cover 884 m before reaching the original vertical level.
Answer:
vr = 5.39 m/s
Explanation:
vi = 16.9 m/s
∅ = 36.5º
d = 16.8 m
g = 9.81 m/s²
vr = ?
We have to get <em>Xmax = R</em> as follows
R = vi²*Sin (2∅) / g
⇒ R = (16.9 m/s)²*Sin (2*36.5º) / (9.81 m/s²)
⇒ R = 27.842 m
Now we can get t, using the formula:
R = vi*Cos ∅*t ⇒ t = R / (vi*Cos ∅)
⇒ t = (27.842 m) / (16.9 m/s*Cos 36.5º) = 2.049 s
We get x (the distance which the receiver must be run) as follows
x = R - d
⇒ x = 27.842 m - 16.8 m = 11.042 m
Finally we have
vr = x / t
⇒ vr = 11.042 m / 2.049 s = 5.39 m/s
Answer:
4520 kJ
Explanation:
To make a substance transition phases an energy must be applied, this is know as the latent heat.
Water has a latent heat of 40.7 KJ/mol to turn into vapor.
The molecule of water has a molecular weight of 18. This means that a mol of water weights 18 grams.
With this we can convert the latent heat to use grams instead of mols
Now, the heat needed to vaporize water is simply:
Q = m * DHvap = 2000 g * 2.26 kJ/g = 4520 kJ
A) The average translational kinetic energy of the molecules in a gas is given by:
where
is the Boltzmann's constant
T is the absolute temperature of the gas
In our problem,
, so the average translational kinetic energy of the molecules is
We have 1.2 mol of this gas, and since one mole of ideal gas contains a number of molecules equal to Avogadro number, the total number of molecules in our gas is
So the total translational kinetic energy of all molecules of the gas is
B) The kinetic energy of a person is given by:
where m is the person's mass and v his velocity. The person has a mass of m=75 kg and its energy is equal to the energy of the gas,
, therefore his velocity must be
Answer:
the frequency of the wave increases