Anytime a scientific theory is challenged does it mean that its not a good theory

The x and y component of a force are 2 and - 3N the force is A) 2i-3j B) 2i+3j C) - 2i-3j D) 3i+2j

There are two boxes on either side of a pulley. One weighs 7.5kg and falls 4.5m in 1.25s. Find that box's acceleration and tension force, and the other box's mass.

Which of the following is a characteristic of a white dwarf star? A) low density B) low volume C) very bright D) very hot E) very cool

A roller coaster at an amusement park has a dip that bottoms out in a vertical circle of radius r. A passenger feels the seat of the car pushing upward on her with a force equal to five times her weight as she goes through the dip. If r = 17.

Compare and contrast fossil fuels and biofuels

A student throws a 5.0-newton ball straight up. What is the net force on the ball at its maximum height? (1) 0.0 N (3) 5.0 N, down (2) 5.0 N, up (4) 9.8 N, down

An object starts from rest and falls freely for 40. meters near the surface of planet P. If the time of fall is 4.0 seconds, what is the magnitude of the acceleration due to gravity on planet P?

Consider two metallic rods mounted on insulated supports. One is neutral, another positively charged. The charged rod is brought close to the neutral one (no touching!

Which term identifies the dark smooth areas on the surface of the moon? craters terrae maria regolith

1. work is a transfer of 2. a small 20-killogram canoe is floating downriver at a speed of 2 m/s. what is the caanoes kinetic energy?