Rosalind mentions to Aliyeh the teacher's talking to Jeremy earlier about "escape speed." Aliyeh had never heard of it, either. Jeremy takes another hit of coffee and says, "Maybe that's what happens if we were to take a spaceship to Mars. We'd have to 'escape' from Earth. Yeah, maybe that's it. What speed does it take to escape from the surface of Earth?

11.2 Km/Sec

Explanation:

Escape velocity is the velocity that one has to achieve to go out of the gravitational effect of a body. Here they are talking about escaping from the Earth's gravity. To travel to Mars, first we will have to go far enough so that the impact of Earth's gravity is negligible.

The escape velocity () can be calculate using the given formula:

where,

G = Gravitational Constant

M = Mass of the object from which we need to escape (Here it is the mass of the Earth)

r = distance from the center of that object (In this case it is equal to the radius of Earth)

For Earth, this comes out to be 11.2 KM/Sec

the answer is a 3.8cm

explanation:

the total distance traveled by the car is

30km + 49km = 79 km .