Problem PageQuestion Archimedes tells us the lifting power of a balloon (how much mass it can lift) is equal to the difference between the mass of the balloon and the mass of the air it displaces. That is, if the balloon occupies the same volume as of air, but the balloon only weighs , then the balloon can lift . Airships have sometimes been filled with hydrogen (), but hydrogen is very flammable, and after the Hindenburg caught fire and crashed in with serious loss of life airships have nearly always been filled with helium () instead.

Aforce of 34.5 newtons is applied to an object at an angle of 45 º with the horizontal. what is the force acting on the object in the horizontal direction?

Explain why the aperture of the spherical mirror should be small compared to the radius of curvature of the mirror.

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?