You are driving at the speed of 31 m/s
(69.3599 mph) when suddenly the car in
front of you (previously traveling at the same
speed) brakes and begins to slow down with
the largest deceleration possible without skid-
ding. considering an average human reaction,
you press your brakes 0.478 s later. you also
brake and decelerate as rapidly as possible
without skidding. assume that the coefficient
of static friction is 0.756 between both cars’
wheels and the road.
the acceleration of gravity is 9.8 m/s
2
.
calculate the acceleration of the car in front
of you when it brakes.
answer in units of m/s
2
.
021 (part 2 of 3) 10.0 points
calculate the braking distance for the car in
front of you.
answer in units of m.
022 (part 3 of 3) 10.0 points
find the minimum safe distance at which you
can follow the car in front of you and avoid
hitting it (in the case of emergency braking
described here).
answer in units of m.

According to social exchange theory, altruistic behaviors benefit the individual who performs them.

In a wind tunnel the speed changes as the cross sectional area of the tunnel changes. if the speed in a 6' x 6' square test section is 100 mph, what was the speed upstream of the test section where the tunnel measured 20' x 20'? use conservation of mass and assume incompressible flow. conservation of mass requires that as the flow moves through a path or a duct the product of the density, velocity and cross sectional area must remain constant; i.e., that ova-constant. a model is being tested in a wind tunnel at a speed of 100 mph if the flow in the test section is at sea level standard conditions, what is the pressure at the model's stagnation point? (a) the tunnel speed is being measured by a pitot-static tube connected to a u- tube manometer. what is the reading on that manometer in inches of water? (b) at one point on the model a pressure of 2058 psf is measured. what is the local airspeed at that point?

Using the work energy theorem. what is the velocity of a 850kg car after starting at rest when 13,000j of work is done to it.