BackA pilot who accelerates at more than begins to 'gray out' but doesn't completely lose consciousness. Assuming constant acceleration, what is the shortest time that a jet pilot starting from rest can take to reach Mach (four times the speed of sound) without graying out? (Use m/s for the speed of sound in cold air.)
In the fastest measured tennis serve, the ball left the racquet at m/s. A served tennis ball is typically in contact with the racquet for ms and starts from rest. Assume constant acceleration. What was the ball's acceleration during this serve?
The fastest measured pitched baseball left the pitcher's hand at a speed of m/s. If the pitcher was in contact with the ball over a distance of m and produced constant acceleration, what acceleration did he give the ball?
An antelope moving with constant acceleration covers the distance between two points m apart in s. Its speed as it passes the second point is m/s. What is its acceleration?
The human body can survive an acceleration trauma incident (sudden stop) if the magnitude of the acceleration is less than m/s2. If you are in an automobile accident with an initial speed of km/h ( mi/h) and are stopped by an airbag that inflates from the dashboard, over what distance must the airbag stop you for you to survive the crash?
When you sneeze, the air in your lungs accelerates from rest to 150 km/h in approximately 0.50 s. What is the magnitude of the acceleration of the air in m/s2?
How far has the car traveled when it reaches 60 mph? Give your answer both in SI units and in feet.
You are driving to the grocery store at 20 m/s. You are 110 m from an intersection when the traffic light turns red. Assume that your reaction time is 0.50 s and that your car brakes with constant acceleration. What magnitude braking acceleration will bring you to a stop exactly at the intersection?
What constant acceleration, in SI units, must a car have to go from zero to 60 mph in 10 s?
For an object starting from rest and accelerating with constant acceleration, distance traveled is proportional to the square of the time. If an object travels 2.0 furlongs in the first 2.0 s, how far will it travel in the first 4.0 s?
You throw a 5.5 g coin straight down at 4.0 m/s from a 35-m-high bridge. What is the speed of the coin just as it hits the water?
A baseball pitcher throws a baseball with a speed of 43 m/s. Estimate the average acceleration of the ball during the throwing motion. In throwing the baseball, the pitcher accelerates it through a displacement of about 3.5 m, from behind the body to the point where it is released (Fig. 2–44).
<IMAGE>
A car traveling 85 km/h slows down at a constant 0.50 m/s² just by 'letting up on the gas.' Calculate the distance it travels during the first and fifth seconds.
A package of mass m is placed onto a horizontal conveyor belt moving at speed v (Fig. 7–32). The coefficient of kinetic friction between package and belt is μₖ. What is the package's displacement d during this time?
(II) An 85-m-long train begins uniform acceleration from rest. The front of the train has a speed of 18 m/s when it passes a railway worker who is standing 180 m from where the front of the train started. What will be the speed of the last car as it passes the worker? (See Fig. 2–45.) <IMAGE>