Si tenemos dos placas paralelas y un campo electrico de 8kN/C entre ellas y además conocemos la separación de estas placas que es igual a 0.03m. Entonces, cuando una carga se mueve de un punto a a un punto b el trabajo que es realizado sobre la carga por el campo eléctrico viene dado por la siguiente ecuación:
Dado que la carga se mueve desde la placa negativa hasta la placa positiva, entonces:
Finalmente, sustituyendo:
Answer:
b) No acceleration in the vertical
c) 35N
d) 35N
e)
Explanation:
a) The situation can be shown in the free body diagram shown in the figure below where F is the applied force, Fr is the friction force, W is the weight of the book and N is the normal force exerted vertically up from the desk to the book
b) The vertical movement is restrained by the normal force which opposes to the weight. In absence of any other force, they both are in equilibrium and the net force is zero
c) The net horizontal force acting on the book is the vectorial sum of the applied force and the friction force. Since they lie in the same axis and are opposed to each other:
d) The net force acting on the book is the vector sum of all forces in all axes. The normal and the weight cancel each other in the y-axis, so our resulting force is the x-axis net force, computed as above:
in the x-axis
e) Following Newton's second law, the acceleration is calculated as
Answer:
(a) -8064 N
(b) 8064 N
Explanation:
(a)
From Newton’s law of motion, Force, F=ma where m is mass and a is acceleration.
Since acceleration is the rate of change of velocity per unit time, then where v is velocity and the subscripts f and I denote final and initial
For the first ball, the mass is 0.28 Kg, final velocity is zero since it finally comes to rest, t is 0.00025 s and initial velocity is given as 7.2 s. Substituting these values we obtain
(b)
For the second ball, the mass is also 0.28 Kg but its initial velocity is taken as zero, the final velocity of the second ball will be equal to the initial velocity of the second ball, that is 7.2 m/s and the time is also same, 0.00025 s. By substitution
Here, we prove that action and reaction are equal and opposite