According to recent typical test data, a Ford Focus travels 0.210 mi in 19.4 s , starting from rest. The same car, when braking from 58.5 mph on dry pavement, stops in 148 ft . Assume constant acceleration in each part of its motion, but not necessarily the same acceleration when slowing down as when speeding up.

a. Find this car's acceleration while braking and while speeding up.
b. If its acceleration is constant while speeding up, how fast (in mph) will the car be traveling after 0.250 mi of acceleration?
c. How long does it take the car to stop while braking from 60.0 mph?

Space-time metric ds2= -dt2+at2dx2+bt2dy2+ct2dz2 (a)how does the area of a rectangle with vertices at ( x=0, y=0, z=0 ), (1,0,0 ), ( 0,1,0 ) and (1,1,0 ) changes with time? (b) if a photon moving in the x direction starts from the origin at t=1, when does it reach x=l? (ds=0 for the trajectory of a photon.) (c) the proper time for a particle is defined by cd=ds. what is the proper time for a particle to move along the trajectory ( x(t)=t, y(t)=0, z(t)=0 ) from t=0 to 1 ? what is the condition on the parameter a so that the velocity of the particle never exceeds the speed of light ?

How does the image distance (di) of a convex lens compare with the image distance of a concave lens? a. the image distance of the convex lens is positive, and that of the concave lens is negative. b. both are negative for a virtual image. c. both are positive for a virtual image d. the image distance of the convex lens is negative, and that of the concave lens is positive.

The diagram shows a series of volcanic island and a hot spot determine the direction of movement of the tectonic plate that for the island