A car reaches 80 km/hr, then suddenly crashed into a concrete wall. Without a seat belt, the crash test dummy slams into the car's dashboard because
A the crash test dummy's kinetic energy drops to zero
B the dashboard is pushed backwards into the crash test dummy
C the crash test dummy continues its motion until acted upon by an unbalanced
force
D Gravity is pulling the crash test dummy in the direction the car is moving

Calculate the molar mass of aluminum oxide (al2o3). express your answer to four significant figures.

Which explanation is true about what happens to a ray of light when it strikes a mirror? a. a light ray is transmitted toward a mirror at a certain angle. the light ray is then reflected by the mirror at an equal angle but in the opposite direction of the transmitted ray. b. an incident ray strikes a mirror at an angle with a line perpendicular to the mirror. the light ray is then reflected at an angle equal to the angle of incidence but on the opposite side of the perpendicular line. c. a reflecting ray strikes a mirror at an angle with a line perpendicular to the mirror. the light ray is then refracted at an angle equal to the angle of the reflecting ray and on the same side of the perpendicular line. d. an incident ray strikes a mirror at an angle with a line parallel to the mirror. the light ray is then transmitted at an angle equal to the angle of incidence but on the opposite side of the parallel line. you so much! : -d take the time to try and answer correctly.

To find the enthalpy of a reaction in the lab, you measured the of the reactants and the change during the reaction.