Answer:
Explanation:
where ΔL is the amount of deformation (the change in length, for example) produced by the force F, and k is a proportionality constant that depends on the shape and composition of the object and the direction of the force. Note that this force is a function of the deformation ΔL—it is not constant as a kinetic friction force is. Rearranging this to
We now move from consideration of forces that affect the motion of an object (such as friction and drag) to those that affect an object’s shape. If a bulldozer pushes a car into a wall, the car will not move but it will noticeably change shape. A change in shape due to the application of a force is a deformation. Even very small forces are known to cause some deformation. For small deformations, two important characteristics are observed. First, the object returns to its original shape when the force is removed—that is, the deformation is elastic for small deformations. Second, the size of the deformation is proportional to the force—that is, for small deformations, Hooke’s law is obeyed. In equation form, Hooke’s law is given by
makes it clear that the deformation is proportional to the applied force. Figure 1 shows the Hooke’s law relationship between the extension ΔL of a spring or of a human bone. For metals or springs, the straight line region in which Hooke’s law pertains is much larger. Bones are brittle and the elastic region is small and the fracture abrupt. Eventually a large enough stress to the material will cause it to break or fracture.
ΔL=
k
F
Answer: The product of mass and velocity is momentum.
Explanation: A good way to summarize momentum is to say momentum is mass in motion. All objects have mass, but not all objects are moving; therefore, not all objects have momentum. If an object is moving, though, it has momentum.
<span>C. the puck's weight and the air blowing </span>
Answer:
<em>she'll be 42.3 years old</em>
<em></em>
Explanation:
The year she left is 2020
she returns in 2040
the time observed to have passed by on earth is 40 years
she traveled at a speed of 2.5 x 10^8 m/s
From relativity, the astronaut will experience a time dilation and will age more slowly.
the time that is observed to pass on her ship will be gotten from
t' =
where t is the time that is observed to pass by an earthly observer
v is the speed of her ship
c is the speed of light = 3 x 10^8 m/s
v/c = 2.5/3 = 0.83
t' = = 40 x 0.5578 = <em>22.3 years</em> would have passed for her
This means that she'll be 20 + 22.3 = <em>42.3 years old</em>
Answer:
Height of the cube under water will be 3.33 cm
Explanation:
We have given height of the cube = 5 cm
Density of the material
Density of liquid
We have to find the height of the cube under the water
Height under water is given by
Height under water =
Height of the cube under water will be 3.33 cm