To calculate the required speed for the car to reach its destination in the desired time, we need to consider the distance already covered and the remaining distance.



The car travels at a speed of 50 km per hour for the first three hours. Therefore, the distance covered in the first three hours can be calculated as:

Distance Covered = Speed * Time
Distance Covered = 50 km/h * 3 hours
Distance Covered = 150 km



To find the remaining distance, we subtract the distance covered in the first three hours from the total distance:

Remaining Distance = Total Distance - Distance Covered
Remaining Distance = 280 km - 150 km
Remaining Distance = 130 km



To calculate the required speed, we divide the remaining distance by the time available:

Required Speed = Remaining Distance / Time Available

We can rearrange the formula to solve for the speed:

Required Speed = 130 km / Time Available

Since the time available is not mentioned in the question, we cannot determine the exact required speed without this information. However, if we assume that the total time available is 4 hours, we can calculate the required speed as:

Required Speed = 130 km / 4 hours
Required Speed = 32.5 km/h

Therefore, if the total time available is 4 hours, the car would need to travel at a speed of 32.5 km per hour after the first three hours to reach the destination in the desired time.

It is important to note that without knowing the time available, we cannot accurately determine the required speed. The answer provided above is based on the assumption of a 4-hour total travel time.

D=280km/hr
Time=3hrs
S=50km/hr
1km=1000m
280*1000=280,000
1hr=3600
3hrs=3600*3=10800
s=D/T
=280,000/10800
=25.9m/s