Question

An object has a mass of 16 x10-9 kg and a charge of -630 nC. It accelerates from a potential of 0 Volts to 5 Volts. How much kinetic energy did it gain? How quickly is it moving?

For the first answer, I got 3.15 *10^-6 J
Second answer I got 19.84 m/s

I am reposting the question because it seems like the previous responders understand my mistake!

Answer 1

To calculate the kinetic energy gained by the object, we can use the formula:

KE = (1/2)mv^2

where KE is the kinetic energy, m is the mass of the object, and v is its velocity.

Plugging in the values, we get:

KE = (1/2)(16 x 10^-9 kg)(309.2 m/s)^2

KE = 7.61 x 10^-6 J

Therefore, the object gained approximately 7.61 x 10^-6 Joules of kinetic energy.

To calculate the velocity of the object, we can use the formula:

ΔPE = qΔV

where ΔPE is the change in electric potential energy, q is the charge of the object, and ΔV is the change in voltage.

Solving for the change in electric potential energy, we get:

ΔPE = (-630 x 10^-9 C)(5 V - 0 V)

ΔPE = -3.15 x 10^-6 J

The change in electric potential energy is equal to the kinetic energy gained by the object, so we can set ΔPE = KE and solve for v:

(1/2)mv^2 = -3.15 x 10^-6 J

v^2 = (-2)(-3.15 x 10^-6 J)/m

v = √(6.30 x 10^-6 J/16 x 10^-9 kg)

v = 309.2 m/s

Therefore, the object is moving at approximately 309.2 meters per second.