Acar traveling down the interstate accelerates to pass a truck. the car accelerates at a rate of 2.8 m/s2 for 3.9 seconds and reaches a speed of 30.9 m/s. calculate how fast the car was going before it accelerated to pass the truck. a 86.5 m. s b 27.7 m/s c 20.0 m/s d 41.8 m/s e 16.3 m/s

2.8 = 30.9 - Initial Velocity  / 3.9

Initial Velocity = 19.98 m/s

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it

r = ρ x length / area  

ρ = r x area / length  

ρ is in ohm-meters  

in basic units, it is m³kg/s³a²  

i think this is it.