Physics

Question 3. An object moves along the axis according to x(t)=t-2*cos(t). Calculate the time dependent instantaneous velocity v(t) and acceleration a(t) Question 4. Find the electric force between two point charges of 4 and 1 Coulombs, separated by a distance of 2 meters, given the Coulomb's constant , q, m Question 5. A small particle mass and charge is released at the distance L from an infinite metal plate with the uniformly distributed surface charge density -p and the magnitude of electrical field (see Figure 1). Assuming that the only force that acts on - P a particle is the Coulomb's force from the plate, calculate acceleration of the particle and choose the correct answer: Figure 1 b) , c) , d) Question 6. Choose the correct statement: a) Momentum of an object is calculated as , where m is its mass and a - its acceleration. b) Kinetic energy of an object is calculated as , where v is its speed and m is its mass. c) Potential energy of a deformed spring that follows Hook's Law is calculated as , where "k" is the stiffness coefficient and "x" is the deformation of the spring. d) none of the above. Question 7. Three point charges q, q and 2q are located as shown in Figure 2. Calculate the fluxes of electrical field through the surfaces A, B, and C and choose the correct answer: b ) c) Figure 2 Question 8. The Coulumb's Law states that the electrical force between the two particles of charges and masses