Question

Q5: A man takes a flight from Lahore at 09:00am and reaches Karachi at
11:40 am. If the distance between Lahore and Karachi is 1920 km calculate
the speed of the plane in m/s and km/hours units.
Ans.​

Answer 1

Required Answer:-

GiveN:

• Departure time = 9:00 am
• Arrival time = 11:40 am
• Distance between the cities = 1920 km.

To FinD:

• Speed of the plant in km/hr and unit conversion$?$

Step-wise-Step Explanation:

We know that, speed is the distance travelled in unit time. Hence, we need to find the distance in km and time in hrs to get the speed of unit km/hr.

• Time = 11:40 am - 9:00 am = 2 2/3 hrs.
• Distance covered = 1920 km

Speed of the man:

⇒ Speed (km/hr) = 1920 km / 2 2/3 hrs

⇒ Speed (km/hr) = 1920 km / 8/3 hrs.

⇒ Speed (km/hr) = 1920 × 3/8 km/hr

⇒ Speed (km/hr) = 720 km/hr

Unit conversion to m/s:

= 720 × 5/18 m/s

= 200 m/s

Hence:-

The speed of the man in km/hrs is 720 km/hr and the speed in m/s is 200 m/s.

Answer 2

Answer:

⠀⠀⠀⌬ Departure Time = 9:00 AM

⠀⠀⠀⌬ Arriving Time = 11:40 AM

⠀⠀⠀⌬ Distance = 1920 km

$\underline{\bigstar\:\textsf{According to the given Question :}}$

$:\implies\sf Distance=Speed \times Time\\\\\\:\implies\sf 1920=Speed \times (11:40AM-9:00AM)\\\\\\:\implies\sf 1920=Speed×2 \:hours \:and \:40 \:minutes\\\\\\:\implies\sf1920 = Speed \times \bigg\lgroup2 + \dfrac{40}{60} \bigg\rgroup\:hours\\\\\\:\implies\sf 1920 = Speed \times \bigg\lgroup2 + \dfrac{2}{3}\bigg\rgroup \:hours\\\\\\:\implies\sf 1920 = Speed \times \dfrac{8}{3}\\\\\\:\implies\sf 1920 \times \frac{3}{8} = Speed\\\\\\:\implies\sf 240 \times 3 = Speed\\\\\\:\implies\sf Speed = 720 \:km/hr$

$\rule{200}{1}$

$\underline{\bigstar\:\textsf{Conversion in meter per second :}}$

$:\implies\sf Speed=720\:km/hr\\\\\\:\implies\sf Speed=720 \times \dfrac{5}{18}\:m/s\\\\\\:\implies\sf Speed = 40 \times 5\:m/s\\\\\\:\implies\sf Speed = 200\:m/s$