KE formula is .5mv^2
So KE=.5mv2
KE=.5(3)(2)^2
KE=.5(3)(4)
KE=.5(12)
KE=6 joules
No; electromagnetic force is the force created by an electrical current attached to a magnet
In your question explains that an accelerometer is a device that uses the extension spring to measure acceleration in terms of Earth's Gravitational accelerations. So if this device is extended just 0.43 centimeters the possible accelerations is letter B. 0.80 g