They are formed by evaporation
Answer:
The average velocity is 180 km/hr
Explanation:
Given;
initial velocity, u = 60 km per hour
final velocity, v = 120 km per hour
initial time = 1 hour
final time = 2 hour
Initial position = 60 km/h x 1 hour = 60 km
final position = 120 km/h x 2 hour = 240 km
The average velocity is given by;

Therefore, the average velocity is 180 km/hr
To solve this problem we will apply the geometric concepts of displacement according to the description given. Taking into account that there is an initial displacement towards the North and then towards the west, therefore the speed would be:


Travel north 2mph and west to 1mph, then,


The route is done exactly the same to the south and east, so make this route twice, from the definition of speed we have to




Therefore the total travel time for the man is 1.15hour.
Answer: D(t)= 50(4/5)^t
Explanation: If 1/5 of the temperature difference is lost each minute, that means 4/5 of the difference remains each minute. So each minute, the temperature difference is multiplied by a factor of 4/5 (or 0.8).
If we start with the initial temperature difference, 50° Celsius, and keep multiplying by 4/5, this function gives us the temperature difference t minutes after the cake was put in the cooler.