To solve the problem it is necessary to apply the definition of Newton's second Law and the definition of density.
Density means the relationship between volume and mass:
While Newton's second law expresses that force is given by
F = ma
Where,
m = mass
a= acceleration (gravity at this case)
In the case of the given data we have to,
In equilibrium, the entire system is equal to zero, therefore
Where,
Weight of balloon
Weight of helium gas
Bouyant force
Then we have,
Replacing the values we have that
Now by ideal gas law we have that
But the relation \frac{n}{m} is equal to the inverse of molar mass, that is
Therefore the pressure of the helium gas assuming it is ideal is 0.61Mpa
Answer:
2.57 seconds
Explanation:
The motion of the ball on the two axis is;
x(t) = Vo Cos θt
y(t) = h + Vo sin θt - 1/2gt²
Where; h is the initial height from which the ball was thrown.
Vo is the initial speed of the ball, 22 m/s , θ is the angle, 35° and g is the gravitational acceleration, 9.81 m/s²
We want to find the time t at which y(t) = h
Therefore;
y(t) = h + Vo sin θt - 1/2gt²
Whose solutions are, t = 0, at the beginning of the motion, and
t = 2 Vo sinθ/g
= (2 × 22 × sin 35°)/9.81
= 2.57 seconds
Answer:
Explanation:
The kinetic energy of a rigid body that travels at a speed v is given by the expression:
The equivalence between mass and energy established by the theory of relativity is given by:
This formula states that the equivalent energy 
can be calculated as the mass 
multiplied by the speed of light 
squared.
Where is approximately 
Hence:
Therefore, the ratio of the person's relativistic kinetic energy to the person's classical kinetic energy is:
Answer:
160N/m
Explanation:
According to Hooke's law which states that the extension of an elastic material is directly proportional to the applied force provided that the elastic limit is not exceeded. Mathematically,
F = ke where
F is the applied force
k is the spring constant
e is the extension
From the formula k = F/e
Since the body accelerates when the block is released, F = ma according to Newton's second law of motion.
The spring constant k = ma/e where
m is the mass of the block = 0.4kg
a is the acceleration = 8.0m/s²
e is the extension of the spring = 2.0cm = 0.02m
K = 0.4×8/0.02
K = 3.2/0.02
K = 160N/m
The spring constant of the spring is therefore 160N/m
Because in reality there are frictional forces acting on the ball, against the direction of its motion. In fact, because of the friction between the ball and the surface, the ball loses little by little its energy, so its velocity decreases and eventually it stops.
In an ideal world with no friction, there would be no forces acting on the ball, so its energy must be conserved and this means that the ball would continue its motion forever.
