Answer:
t = 2.38 [s]
Explanation:
To solve this problem we must use the following equation of kinematics. We must clarify that both the acceleration and the initial velocity were taken as positive, since the velocity of the movement coincides with the direction of the acceleration.
where:
x - Xo = distance = 47 [m]
Vo = initial velocity = 8 [m/s]
a = gravity acceleration = 9.81 [m/s²]
t = time [s]
Now replacing these values in the equation:
47 = 8*t + 0.5*9.81*t²
47 = 8t + 4.905t²
47 = 4.905*t(1.63 + t)
9.58 = t*(1.63 + t) solving this equation (cuadratic)
we found that t = 2.38 [s]
Answer:
B . 68.7 N
Explanation:
Given in the question that;
Force = 22 N
Mass = 7.0 kg
Velocity = 4.0 m/s
Gravitational force is the weight of wooden block , calculated as mass times acceleration due to gravity.
F= m* a
F= 7 * 9.81
F= 68.67 N
F= 68.7 N
Explanation:
The charge (positive or negative) is always on the surface in the conductors. So, if the plates have substantial thickness, the charge is distributed throughout the surface. We know from the question that the bottom plate is charged positively, so an equal amount of negative charge must be distributed on the lower surface of the upper plate.
The direction of the E-field is always directed from positive to the negative charge. Since the plates have flat surfaces, the electric field lines are straight, except the edges. In most college level questions this effect is negligible, that is why in most questions the plates are considered very large.
Taking into account the definition of electron affinity, negative electron affinity means that the anion of the element is more stable than the neutral atom.
Electron affinity is the energy exchanged when a neutral, gaseous atom, and in its ground state, captures an electron to form the anion.
In other words, electronon Affinity is the energy that is given off when a neutral atom in the gaseous state captures an electron to become a negative ion.
The value can be positive or negative. A negative electron affinity means energy must enter in order to bind an electron to the ion, being an endothermic process. If electron affinity is positive, the process is exothermic and occurs spontaneously.
Then, the negative electron affinity (energy is released) occurs when the atoms acquire a more stable configuration when capturing an electron, so the attractive force will predominate. Positive electron affinity (energy is absorbed): occurs when you have to provide energy to the atom to capture the ion.
In summary, negative electron affinity means that the anion of the element is more stable than the neutral atom.
Learn more:
Explanation:
K.E. of marble 1 = (1/2) × 0.2 × (22/0.8) ^2
= 0.1 × 756.25
= 75.625
K.E. of marble 2 = (1/2) × 1.2 × (26/0.8)^2
= 0.6 × 1056.25
= 633.75