When a bird flips it swings which direction does the air push against the birds wings

Which type of electromagnetic waves are dangerous enough to be used to kill cancerous cells? (a)gamma rays (b)visible light (c)infrared light (d)microwaves

What are the factors that affect the resistance of a wire?

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