Find the average velocity if the takeoff velocity of an airplane on a runway is 300 km/hr with an acceleration of 1 m/s2 . A) 30 sec B) 41.7 sec C) 72.2 sec D) 83.33 sec

You have to decide what you want.  Your question says "Find the average velocity", but the choices you listed are all times, not velocities.

(300 km/hr) x (1 hr / 3600 sec) = 83.33 meters/sec

-- If the airplane starts from rest and accelerates uniformly at 1 m/s², it'll take 83.33 seconds to reach takeoff speed.

-- If it starts from rest and accelerates uniformly to 83.33 m/s, then its average speed is 41.67 m/s no matter what its acceleration may be.

Current, I = 20 Amperes.

Explanation:

Given the following data;

Voltage = 40 V

Resistance = 2 Ohms

To find current flowing through the resistor;

Ohm's law states that at constant temperature, the current flowing in an electrical circuit is directly proportional to the voltage applied across the two points and inversely proportional to the resistance in the electrical circuit.

Mathematically, Ohm's law is given by the formula;

Where;

V represents voltage measured in voltage.

I represents current measured in amperes.

R represents resistance measured in ohms.

Making current (I) the subject of formula, we have;

Substituting into the formula, we have;

Current, I = 20 Amperes.