How is the question in the photo

To run the physics cart, the fan speed of the cart is manipulated. this is the (blank) variable. the cart accelerates due to the speed of the fan. acceleration is therefore the (blank) variable. a “constant” is a parameter that stays the same regardless of the variables. one parameter of the cart that is held constant is the (blank) .

Which subatomic particle has a negative charge

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.