Answer:
350 N/m
Explanation:
If we are assuming the stretch does not exceed the elastic range of the material, then by Hooke's law the spring constant of the cord is simply the ratio between the force 70N acting on the cord to stretch 20cm or 0.2m
k = 70 / 0.2 = 350 N/m
The spring constant is 350 N/m
Answer:
11.625
Explanation:
L = length of the ladder = 16 ft
= rate at which top of ladder slides down = - 3 ft/s
= rate at which bottom of ladder slides
y = distance of the top of ladder from the ground
x = distance of bottom of ladder from wall = 4 ft
Using Pythagorean theorem
L² = x² + y²
16² = 4² + y²
y = 15.5 ft
Also using Pythagorean theorem
L² = x² + y²
Taking derivative both side relative to "t"



= 11.625 ft/s
Answer:
(b) The electrons, because they have the smaller momentum and, hence, the larger de Broglie wavelength
Explanation:
de Broglie wavelength λ = h / m v
Since both electrons and protons have same velocity , momentum mv will be less for electrons because mass of electron is less .
for electron , momentum is less so . Therefore de Broglie wavelength λ will be more for electrons .
Amount of diffraction that is angle of diffraction is proportional to λ
Therefore electrons having greater de Broglie wavelength will show greater diffraction.
Answer:
B. 24.2 m/s
Explanation:
Given;
mass of the roller coaster, m = 450 kg
height of the roller coaster, h = 30 m
The maximum potential energy of the roller coaster due to its height is given by;



Therefore, the maximum speed of the roller coaster is 24.2 m/s.
That's efficiency. There's no law that it must be stated in percent.