A tennis player tosses a tennis ball straight up and then catches it after 1.77 s at the same height as the point of release. (a
1 answer:
(a) 9.8 m/s^2, downward
There is only one force acting on the ball while it is in flight: the force of gravity, which is
F = mg
where
m is the mass of the ball
g is the gravitational acceleration
According to Newton's second law, the force acting on the ball is equal to the product between the mass of the ball and its acceleration, so
F = mg = ma
which means
a = g
So, the acceleration of the ball during the whole flight is equal to the acceleration of gravity:
g = -9.8 m/s^2
where the negative sign means the direction is downward.
(b) v = 0
Any object thrown upward reaches its maximum height when its velocity is zero:
v = 0
In fact, at that moment, the object's velocity is turning from upward to downward: that means that at that instant, the velocity must be zero.
(c) 8.72 m/s, upward
The initial velocity of the ball can be found by using the equation:
v = u + at
Where
v = 0 is the velocity at the maximum height
u is the initial velocity
a = g = -9.8 m/s^2 is the acceleration
t is the time at which the ball reaches the maximum height: this is half of the time it takes for the ball to reach again the starting point of the motion, so
So we can now solve the equation for u, and we find:
(d) 3.88 m
The maximum height reached by the ball can be found by using the equation:
where
v = 0 is the velocity at the maximum height
u = 8.72 m/s is the initial velocity
a = g = -9.8 m/s^2 is the gravitational acceleration
d is the maximum height reached
Solving the equation for d, we find
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Answer:
they meet from the girl's original position at: 2.37 (meters)
Explanation:
We need to use the Newton's law, exactly the second law that relate force, mass and acceleration as: with this we can get both accelerations; solving for acceleration
. Now
and
. Then knowing that they both travel at the same time and assuming that the distance among the girl and the sled is: 15.0-x, so,
and
, solving for the time we get:
and
with this equations we solving for the x that is the distance between the girl and the sled after the apply the force and we get:
. Finally we get:
and replacing the values we have got:
so
so x=2.37 (meters).
La masa molar de 65 litros de SO2 es igual a 64,1 g/mol.
<h3>Masa molar</h3>
La masa molar de un compuesto depende de su masa presente en 1 mol, entonces:
Para calcular la masa molar de un compuesto, simplemente suma las masas de cada elemento en el compuesto, así:
Así, la masa molar de 65 litros de SO2 es igual a 64,1 g/mol.
Obtenga más información sobre la masa molar en: brainly.com/question/17109809
At the point of maximum displacement (a), the elastic potential energy of the spring is maximum:
while the kinetic energy is zero, because at the maximum displacement the mass is stationary, so its velocity is zero:
And the total energy of the system is
Viceversa, when the mass reaches the equilibrium position, the elastic potential energy is zero because the displacement x is zero:
while the mass is moving at speed v, and therefore the kinetic energy is
And the total energy is
For the law of conservation of energy, the total energy must be conserved, therefore
. So we can write
that we can solve to find an expression for v:
while the kinetic energy is zero, because at the maximum displacement the mass is stationary, so its velocity is zero:
And the total energy of the system is
Viceversa, when the mass reaches the equilibrium position, the elastic potential energy is zero because the displacement x is zero:
while the mass is moving at speed v, and therefore the kinetic energy is
And the total energy is
For the law of conservation of energy, the total energy must be conserved, therefore
that we can solve to find an expression for v: