A 61 kg skateboarder is moving down a ramp with a 7 m radius of curvature. At the bottom of this ramp, she reaches a speed of 7.8 m/s. What upward force acts on the skateboarder at the bottom of the ramp?

Pls pls pls pls ! describe, in your own words, how you found the epicenter of the earthquake.

Astudent creates a model of a closed ecosystem by filling a glass tank half full with water, then adding 10 snails and two small aquatic plants. the next day, all the snails are dead. what is the most likely cause of their death?

Assume you measured the mass of the cart to be (500 ± 1) g and the mass of the additional mass you put on the cart to be (500 ± 1) g as well. since the scale you are using in the lab cannot measure objects heavier than 600g you will have to sum up individual pieces and propagate the error. so what would be the mass and the standard error of the cart and the mass