Athin layer of oil of refractive index 1.30 is spread on the surface of water (n = 1.33). if the thickness of the oil is 210 nm, then what is the wavelength of light in air that will be predominantly reflected from the top surface of the oil?

Arunner is training for an upcoming marathon by running around a 100-m-diameter circular track at constant speed. let a coordinate system have its origin at the center of the circle with the x-axis pointing east and the y-axis north. the runner starts at (x, y) = (50 m, 0 m) and runs 2.5 times around the track in a clockwise direction.

Compare the horizontal displacement of the two balls as they travel to the ground. what do you observe?

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