I looked up the question and got D- a vacuum
Answer:
270 mi/h
Explanation:
Given that,
To the south,
v₁ = 300 mi/h, t₁ = 2 h
We can find distance, d₁

To the north,
v₂ = 250 mi/h, d₂ = 750 miles
We can find time, t₂

Now,
Average speed = total distance/total time

Hence, the average speed for the trip is 270 mi/h.
Answer:
9.4 x 10⁴ m/s
Explanation:
In circular or elliptical orbits , the angular momentum is conserved because torque is zero.
mr₁v₁ = mr₂v₂
2.2 x 10¹¹ x 1.8 x 10⁴ = 4.2 x 10¹⁰ v₂
v₂ = 9.42 x 10⁴ m/s.
= 9.4 x 10⁴ m/s
Momentum (in terms of classical mechanics) is defined as p = m*v, where m is the mass and v is the velocity.