Charge in an Electric Field: A pair of charged conducting plates produces a uniform field of 12,000 N/C, directed to the right, between the plates. The separation of the plates is 40 mm. An electron is projected from plate A, directly toward plate B, with an initial speed of v0 = 2.0 × 107 m/s. What is the speed of the electron as it strikes plate B? (e = 1.6 × 10-19 C, melectron = 9.11 × 10-31 kg)

Explanation:

Force on charge in electric field = q E , q is charge and E is electric field

= 1.6 x 10⁻¹⁹ x 12000

= 19200 x 10⁻¹⁹ N

acceleration = force / mass

=  19200 x 10⁻¹⁹ / 9.1 x 10⁻³¹

a = 2109.9 x 10¹² m /s²

initial velocity of electron u = 2 x 10⁷ m /s

v² = u² + 2as  ( s is distance between plate , u is initial velocity )

v² = ( 2 x 10⁷)² + 2 x 2109.9 x 10¹² x 40 x 10⁻³

= 4 x 10¹⁴ + 1.68 x 10¹⁴

= 5.68 x 10¹⁴

v = 2.38 x 10⁷ m /s

which piece of furniture will have the most inertia and give the furniture movers the most difficulty in moving?  

answer

a 75kg dining table

  the unit of the measure =

explanation:

  the property that is quantified by the energy needed per of material to raise the temperature by one.

  si unit of energy = joule (j)

  si unit of temperature = kelvin (k)

  si unit of mass of material = kilogram (kg)

the property that is quantified by the energy needed per of material to raise the temperature by one is called specific heat.

the unit of specific heat is