How much force is needed to accelerate a 7.1 kg skier at 4 m/s/s?

Which quantities are scalars? choose all that apply a.distance b.speed c. acceleration d.velocity

Very large accelerations can injure the body, especially if they last for a considerable length of time. one model used to gauge the likelihood of injury is the severity index ( ), defined as =/ . in the expression, is the duration of the accleration, but is not equal to the acceleration. rather, is a dimensionless constant that = the number of multiples of that the acceleration is equal to.in one set of studies of rear-end collisions, a person's velocity increases by 13.7 km/h with an acceleration of 36.0 m/s2 . let the + direction point in the direction the car is traveling. what is the severity index for the collision?

What are similarities and differences between refraction, reflection, diffraction and absorption?