Final answer:
Earth's escape velocity of 11.2 km/s is equivalent to 11,200 m/s and 40,320 km/h, corresponding to choice (b) in the question.
Step-by-step explanation:
The escape velocity of any object from Earth is 11.2 km/s. To express this speed in meters per second (m/s), simply convert kilometers to meters by multiplying by 1,000. Thus, 11.2 km/s is equal to 11.2 × 1,000 m/s, which is 11,200 m/s.
To convert the escape velocity to kilometers per hour (km/h), multiply by the number of seconds in an hour since 1 hour = 3,600 seconds. So, 11.2 km/s × 3,600 sec/hour gives you 40,320 km/h.
The escape velocity of Earth is 11.2 km/s. To express this speed in m/s, we need to convert kilometers to meters. Since 1 km = 1000 m, we multiply 11.2 km/s by 1000 to get 11,200 m/s.
To express this speed in km/h, we need to convert seconds to hours. There are 3600 seconds in an hour. So, 11.2 km/s multiplied by 3600 gives us 40,320 km/h.
Therefore, the correct expressions for Earth's escape velocity in m/s and km/h are 11,200 m/s and 40,320 km/h respectively, matching choice (b).