Which of the following is true about elements? a. atoms of all elements contain the same number of protons, but the number of neutrons is different for every element. b. atoms of all elements contain neutrons, but they do not all contain protons. c. atoms of all elements contain electrons, but they do not all contain protons. d. atoms of all elements contain protons, but the number of protons is different for every element.

When considering gravity acceleration and the force of acceleration, what must be true? a. the direction of acceleration must be perpendicular to the direction of the force. b. the direction of the force and the direction of acceleration must be the same as each other. c. the direction of the force and the direction of acceleration must be opposite of each other. d. the mass of the body must be the same as the acceleration of the body.

Determine the change in width a, height b, thickness t when a plate is subjected to the uniform distributed load and is made of material having modulus of elasticity e=230 gpa and poisson's ratio ν=1/3. given : a=400 mm and b= 300 mm also the uniformly distributed load in downward y direction of plate is 2 mn/m and in the positive x direction is 3 mn/m and t=20 mm

Who was the first scientist to measure speed as distance over time?