Which sentence provides evidence that heat travels from Earth’s mantle up to its crust?
A.
Earth’s atmosphere is warmer during the day than at night.
B.
Earth’s outer surface is cooler than its interior layers.
C.
Rocks and other objects on Earth’s surface heat up quickly in the afternoon sun.
D.
The core of Earth is solid, but the layer just beneath Earth's crust is molten.

Arunner is jogging at a steady 3.6 km/hr. when the runner is 2.9 km from the finish line, a bird begins flying from the runner to the finish line at 14.4 km/hr (4 times as fast as the runner). when the bird reaches the finish line, it turns around and flies back to the runner. even though the bird is a dodo, we will assume that it occupies only one point in space, i.e., a zero-length bird. how far does the bird travel? (b) after this first encounter, the bird then turns around and flies from the runner back to the finish line, turns around again and flies back to the runner. the bird repeats the back and forth trips until the runner reaches the finish line. how far does the bird travel from the beginning? (i.e. include the distance traveled to the first encounter)