Hello
The weight of the object is W=80 N and points downwards, in the vertical direction. The force F exerted by the forearm is perpendicular to the forearm itself, which is at an angle of
above the horizontal; therefore, the angle between the direction of the force F and the direction of the weight P is also
(but upwards). The component of the force F in the vertical direction is
and
must be equal to the weight of the object to compensate it. Therefore we can write
and from this we can find the intensity of the force F:
Answer:
Solution A is 1 x 10⁵ times more acidic than solution B
Explanation:
The pH scale is a logarithmic scale used to express the acidity or basicity of a solution.
The values are written from 1 - 14 with 1 being the most acidic and 14 a basic solution.
Each interval is ten folds more concentrated than the next because it is a logarithmic scale.
Since the pH of A = 3.4
pH of B = 8.4
The difference = 8.4 - 3.4 = 5.0
So, Solution A is 1 x 10⁵ times more acidic than solution B
Answer:
re = 2.09 Å.
Explanation:
As the electron is moving around the stationary proton along a circular path at a constant speed, there exists a force that keeps the electron within this trajectory, which is the centripetal force.
This centripetal force, is no other than the attractive electric force between the proton and the electron, so we can write the following equality:
Fe = Fc ⇒ k*Qp*Qe / re² = me*ve²/re
⇒ re = k*Qp*Qe / m*ve², where:
k = 9*10⁹ N, Qp =-Qe= 1.6*10⁻¹⁹ coul, me =9.1*10⁻³¹ kg, and ve= 1.1*10⁶m/s
⇒ re = 9*(1.6)²*10⁻²⁹ / 9.1*(1.1)²*10⁻¹⁹ m
⇒ re = 2.09*10⁻¹⁰ m = 2.09 Å.
Um what exactly is this???