Problem 7.17 A horizontal spring with stiffness 0.8 N/m has a relaxed length of 12 cm (0.12 m). A mass of 23 grams (0.023 kg) is
1 answer:
The speed of the mass v = 0.884 m/s.
<u>Explanation</u>:
Let
K1 represents the kinetic energy of the mass when it is released,
U1 represents the potential energy of the spring when the mass is released,
K2 represents the kinetic energy of the mass when the spring returns to relaxed length,
U2 represents the potential energy of the spring when the spring returns to relaxed length
The spring is stretched by 0.27 - 0.12 = 0.15 m
K1 = 0
U1 = (1/2) 0.8
(0.15)^2
= 0.009 J
U2 = 0
By conservation of energy,
K2 + U2 = K1 + U1
K2 + 0 = 0 + 0.009 J
K2 = 0.009 J
Let v = speed of the mass
K2 = 1/2 m
v^2
m = 23 g = 0.023 kg
0.009 = 1/2 0.023
v^2
0.009 = 0.0115 v^2
v = √(0.009 / 0.0115)
v = 0.884 m/s.
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Answer:
t=0.42s
Explanation:
Here you have an inelastic collision. By the conservation of the momentum you have:
m1: mass of the bullet
m2: wooden block mass
v1: velocity of the bullet
v2: velocity of the wooden block
v: velocity of bullet and wooden block after the collision.
By noticing that after the collision, both objects reach the same height from where the wooden block was dropped, you can assume that v is equal to the negative of v2. In other words:
Where you assumed that the negative direction is upward. By replacing and doing v2 the subject of the formula you get:
Now, with this information you can use the equation for the final speed of an accelerated motion and doing t the subject of the formula. IN other words:
hence, the time is t=0.42 s
Answer:
The answers are located in each of the explanations showed below
Explanation:
a)
(i) Surface Tension: The tensile force that causes this tension acts parallel to the surface and is due to the forces of attraction between the molecules of the liquid. The magnitude of this force per unit of length is called surface tension.
σ = F/l [N/m]
where:
F = force [N]
l = length [m]
σ = Surface Tension [N/m]
(ii) Frequency is the number of repetitions per unit of time of any periodic event.
f = 1/T [1/s] or [s^-1] or [Hz]
where:
T = period [s] or [seconds]
f = frecuency [Hz] or [hertz]
(iii) Each of the units will be shown for each variable
v = velocity [m/s]
a = accelertion [m/s^2]
s = displacement [m]
b) To find the velocity we must derivate the function X with respect to t because this derivate will give us the equation for the velocity, it means:
ii) replacing in the derivated equation.
iii) the average velocity is defined by the expresion v = x/t
2
a) Pascal's principle or Pascal's law, where the pressure exerted on an incompressible fluid and in balance within a container of indeformable walls is transmitted with equal intensity in all directions and at all points of the fluid.
Therefore:
P1 = pressure at point 1.
P2 = pressure at point 2.
P1 = F1/A1
P2= F2/A2
b) One of the applications of the surface tension is the <u>capillarity</u> this is a property of liquids that depends on their surface tension (which, in turn, depends on the cohesion or intermolecular force of the liquid), which gives them the ability to climb or descend through a capillary tube.
Other examples of surface tension:
The mosquitoes that can sit on the water.
A clip on the water.
Some leaves that remain floating on the surface.
Some soaps and detergents on the water.