When did life first appear on Earth?
a. 14 billion years ago
b. 400 million years ago
c. 4.6 billion years ago
d. 65 million years ago
e. 3.4 billion years ago
e
You might also like to view...
Superposition of waves can produce
A) reinforcement. B) cancellation. C) partial cancellation. D) all the above
The least massive red main-sequence stars may have lifetimes of a trillion years
Indicate whether the statement is true or false
Consider the data points together with the models in the graph of expansion models. Which model is most strongly supported by the data?
A) accelerating B) critical C) recollapsing D) coasting Refer to this scenario for the following questions: A multi-dimensional being reaches down to Earth and pulls you out of the universe. You are then thrown back into the universe at a place and time of the being's choosing, and you are permitted to leave only after you have identified your surroundings. This process is repeated several times. Through a scientifically unexplainable miracle, you are able to survive in every one of the places that you find yourself. In each scenario below, identify your surroundings (and potentially your cosmic era) from among the choices given.
The intensity of light from the Sun is 1.3 kW/m2 at the distance of the Earth. The Earth's radius is 6.4 × 10^6 m. If all the sunlight that hits the Earth were absorbed, what would be the magnitude of the resulting force on the Earth?
a. 0.0087 N b. 1.8 × 10^8 N c. 5.6 × 10^8 N d. 87 N