In one of the classic nuclear physics experiments performed by Ernest Rutherford at the beginning of the 20th century, alpha particles (helium nuclei) were shot at gold nuclei and their paths were substantially affected by the Coulomb repulsion from the nuclei. show answer Incorrect Answer If the energy of the (doubly charged) alpha nucleus was 5.1 MeV, how close to the gold nucleus (79 protons) could it come before being deflected? r =

Basilisk lizards can run across the top of a water surface (see the figure). with each step, a lizard first slaps its foot against the water and then pushes it down into the water rapidly enough to form an air cavity around the top of the foot. to avoid having to pull the foot back up against water drag in order to complete the step, the lizard withdraws the foot before the water can flow into the air cavity. if the lizard is not to sink, the average upward impulse on the lizard during this full action of slap, downward push, and withdrawal must match the downward impulse due to the gravitational force. suppose the mass of a basilisk lizard is 93.7 g, the mass of each foot is 3.37 g, the speed of a foot as it slaps the water is 1.15 m/s, and the time for a single step is 0.531 as. (a) what is the magnitude of the impulse on the lizard during the slap