An automobile has a mass of 2100 kg and a velocity of +17 m/s. it makes a rear-end collision with a stationary car whose mass is 1900 kg. the cars lock bumpers and skid off together with the wheels locked. (a) what is the velocity of the two cars just after the collision? (b) find the impulse (magnitude and direction) that acts on the skidding cars from just after the collision until they come to a halt. (c) review: if the coefficient of kinetic friction between the wheels of the cars and the pavement is μk = 0.68, determine how far the cars skid before coming to rest.

An isolated conducting spherical shell carries a positive charge. part a which statement (or statements) about the electric field and the electric potential inside and outside the spherical shell is correct? which statement (or statements) about the electric field and the electric potential inside and outside the spherical shell is correct? electric potential inside the shell is constant and outside the shell is changing as 1/r2 both the electric potential and the electric field does change with r inside and outside the spherical shell electric potential inside and outside the shell is constant, but not zero electric potential inside the shell is constant and outside the shell is equal to zero electric field inside and outside the shell is constant (does not change with the position r), but is not equal to zero electric field inside and outside the shell is changing as 1/r (where r is the distance from the center of the sphere) electric field inside is equal to zero and outside the shell is constant, but not zero electric potential inside the shell is constant and outside the shell is changing as 1/r electric field inside and outside the shell is changing as 1/r2 electric field inside is equal to zero and outside the shell is changing as 1/r2 electric field inside and outside the shell is zero electric field inside is constant and outside the shell is changing as 1/r