Help with physics please...?

Question

I only have 2 problems left on my homework...

K=1/2(6.6 x 10^2 kg)(2.11 x 10^4 m/s)^2

F=(9.0 x 10^9 N m^2/C^2) [(3.2 x 10^ -9 C)(9.6 x 10^-9 C)/(0.32)]

my big problem is i dont know what the units are going to be.

Answer with most detail will get best

thanks in advance

Answer 1

E = 1/2mv2 - energy is measured in Joules (J)

Force is measured in Newtons (N)

Answer 2

All units you wrote  (kg, m, s, N, C) were SI units, so the units for K and F must be SI units.

Unit for kinetic energy K is joule (J)

Unit for electrostatc force F is newton (N)

Answer 3

KE = ½mv²

K=½ (6.6e2  kg) (2.11e4 m/s)²

K = (3.3e2) (4.4521e8) kg m²/s²

K = 14.69193e10 kg m²/s²

1 J = 1 kg m²/s²

K = 14.69193e10 J

________________

Fe = k q1q2/r²

Did you mean (.32 m)²?

F = (9.0e9 N m²/C²) [(3.2e-9 C) (9.6e-9 C) / (.32 m)²]

The C's and m's cancel out, leaving N:

F = 0.0000027 N

F = 2.7e-6 N

Answer 4

In the metric system, energy is in Joules and force is in Newtons.  

Answer 5

Kinetic energy has SI units of Joules (J). The reasons for that are the following:

- One Joule equals one Newtons x meter.

- Multiplying kilograms by meters squared per seconds squared gives you kilograms time meters per second squared times meters. Of course, the product of kilograms and meters per second squared gives you Newtons. And multiplying that by meters gives you Joules.

Force has SI units of Newtons (N). In this case, you get Newtons because:

- Multiplying two units of Coulombs gives you squared Coulombs. Multiplying that to the Coulomb constant cancels units of squared Coulombs. After dividing by something with units of meters squared gives you Newtons.

EDIT: Here it is solved.

K = 0.5 x 660 kg x (21,100 m/s)² = 1.47 x 10^11 J

F = ((9.0 x 10^9 Nm²/C²) x (3.2 x 10^-9 C) x (9.6 x 10^-9 C)) / (0.32 m)² = 2.7 x 10^-6 N