To test the performance of its tires, a car
travels along a perfectly flat (no banking) cir-
cular track of radius 564 m. the car increases
its speed at uniform rate of
a 101
al = 410 = 3.62 m/s2
dt
until the tires start to skid.
if the tires start to skid when the car reaches
a speed of 35 m/s, what is the coefficient of
static frictionsbetween the tires and the road?

Along wire carrying a 4.2 a current perpendicular to the xy-plane intersects the x-axis at x=−1.7cm. a second, parallel wire carrying a 3.0 a current intersects the x-axis at x=+1.7cm. part a at what point on the x-axis is the magnetic field zero if the two currents are in the same direction? express your answer to two significant figures and include the appropriate units.

Estimate of the number of stars in our galaxy

You have two photos of a person walking. one shows the person at the corner of third and main streets, the other shows the person at the corner of tenth and main streets. there are lampposts at every corner in this town, and the first picture shows it to be 10: 32: 00 exactly. the second picture shows it to be 10: 49: 30. you know three facts: (1) all of the clocks are synchronized; (2) there are exactly 12 equal-sized blocks per kilometer in this town; and (3) the streets that cross main in this area are numbered consecutively, with no interruptions. what is the person’s average speed in kilometers per hour?