Which of the following is the best definition of an isotope?

A. elements of the same kind with different numbers of neutrons

B. elements of the same kind that have lost electrons

C.

elements of the same kind that have different electrical charges

200mg of uranium-238 has a half life of 4.5 billion years How much will be left after 13.5 billion years

Which statements describe vectors? Check all that apply. - Vectors have magnitude only. - Vectors have direction only. - Vectors have both magnitude and direction. - Vectors are drawn using a curved line. - Vectors are drawn using an arrow.

During a tennis serve, a racket is given an angular acceleration of magnitude 150 rad/s^2. At the top of the serve, the racket has an angular speed of 12.0 rad/s. If the distance between the top of the racket and the shoulder is 1.

2. According to the passage, the Afar Depression is a. A really sad place far away b. A vast desert in northeast Ethiopia, a country in Africa c. A lake of boiling lava d. A place where two continents collide

Newton's universal law of gravitation says that every object exerts a force on another object. The shuttle has a gravitational force with Earth, the moon, and whatever planet it is near. This force prevents the shuttle from drifting.

An ant sits on the back of a mouse. The mouse carries the ant across the floor for a distance of 10 m. Was there work done by the mouse? Explain.

How does the strong nuclear force compare with the electrostatic force in the nucleus of an atom? A. The strong nuclear force is stronger and is only attractive. B. The strong nuclear force is weaker and acts over longer distances. C.

A 1100 - kg car collides with a 1300 - kg car that was initially at rest at the origin of an x-y coordinate system. After the collision, the lighter car moves at 20.0 km/h in a direction of 30 o with respect to the positive x axis.

Which of the following is the best definition of an isotope? A. elements of the same kind with different numbers of neutrons B. elements of the same kind that have lost electrons C. elements of the same kind that have different electrical charges

A light plane must reach a speed of 33m/s for takeoff. how long a runway is needed if the the acceleration is 3.0m/s^2