Which of these is NOT a good hypothesis? * The increase in carbon dioxide is due to the increase in fossil fuel use.

Dinosaurs were much friendlier than people have imagined.

Volcanoes increase the amount of carbon dioxide in the atmosphere.

It's a snowy day and you're pulling a friend along a level road on a sled. you've both been taking physics, so she asks what you think the coefficient of friction between the sled and the snow is. you've been walking at a steady 1.5m/s, and the rope pulls up on the sled at a 32 ∘ angle. you estimate that the mass of the sled, with your friend on it, is 65 kg and that you're pulling with a force of 80 n .