A plane is flying at 600 km/h and reduces its velocity uniformly to 70 km/h in 3 minutes. What is its acceleration?

To determine the acceleration of the plane, you need to calculate the change in velocity and the time over which that change occurs.

First, convert the speeds from kilometers per hour to meters per second, because acceleration is typically expressed in meters per second squared (m/s²).

The initial velocity (u) is 600 km/h, which can be converted as follows:

600 km/h × (1000 m/km) ÷ (3600 s/h) = 166.67 m/s

The final velocity (v) is 70 km/h, converted in the same way:

70 km/h × (1000 m/km) ÷ (3600 s/h) = 19.44 m/s

Now, calculate the change in velocity (Δv):

Δv = v - u = 19.44 m/s - 166.67 m/s = -147.23 m/s

The time (t) taken for this change is given as 3 minutes, which also needs to be converted into seconds:

3 minutes × 60 seconds/minute = 180 seconds

Now, according to the formula for acceleration (a), which is defined as the change in velocity divided by the time taken for that change: