ALWAYS use significant figure rules. Remember that these rules apply to all numbers that are measurements.

A missile is fired from a jet flying horizontally at Mach 2 (2200 ft/s). The missile has a horizontal acceleration of 1000 ft/s2. Calculate its horizontal velocity at 10.0 seconds after it is fired. (Assume constant acceleration of the missile throughout its flight.)
12,200 ft/s
10,000 ft/s
2300 ft/s
7800 ft/s
my answer is 2300 ft/s

V = Vo + a*t = 2200 + 1000*10 = 12,200 ft/s.

To calculate the horizontal velocity of the missile at 10.0 seconds after it is fired, we can use the formula:

velocity = initial velocity + (acceleration * time)

Given:
Initial velocity (u) = 2200 ft/s (Mach 2 is approximately 2200 ft/s)
Acceleration (a) = 1000 ft/s^2
Time (t) = 10.0 seconds

Using the formula, we can substitute the values:

velocity = 2200 ft/s + (1000 ft/s^2 * 10.0 s)

velocity = 2200 ft/s + (10000 ft/s)

velocity = 12200 ft/s

Therefore, the horizontal velocity of the missile at 10.0 seconds after it is fired is 12200 ft/s.

Based on your options, the correct answer is indeed 12200 ft/s.