A girl stands on a moving sidewalk (conveyor belt) that is moving to the right at a speed of 2 m/s relative to the ground. A dog runs on the belt toward the girl at a speed of 8 m/s relative to the belt. What is the speed of the dog relative to the ground?

Explanation:

Given

Speed of elevator is given by

Dog is running towards the girl with velocity w.r.t sidewalk

Therefore velocity of dog w.r.t ground

the focus of lesson 1 is newton's first law of motion - sometimes referred to as the law of inertia. newton's first law of motion is often stated as. an object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

explanation:

it is the second option.