Answer:
a = kL/m
Explanation:
Here we can use Hooke's Law to find out the force applied on the system. Hooke's Law states that when a spring is stretched by some force, the force applied is directly proportional to the displacement of spring. The formula is given as:
F = kL
Now, the Newton's Second Law of motion states that whenever an unbalanced force is applied to a body it produces an acceleration in the body, in its own direction. So, the force is given by the formula:
F = ma
Comparing both the forces, we get:
kL = ma
<u>a = kL/m</u>
Let's use ' t ' to represent half of the time, in hours.
The distance traveled in the first half of the time is (80 t) km.
The distance traveled in the last half of the time is (40 t) km.
The total distance covered is (80t + 40t) = (120t) km.
You said that the total distance covered was 60 km,
so ...
120 t = 60 km
Divide each side by 120 : t (half of the time) = 0.5 hour
Average speed = (total distance covered) / (time to cover the distance)
= (60 km) / (1 hour)
= 60 km/hr .
