A car traveling 89 km/h strikes a tree. The front end of the car compresses and the driver comes to rest after traveling 0.81 m. a) What was the average acceleration of the driver during the collision? b) Express the answer in terms of g.

You can perform a popular trick by dropping any peso bill (Ex. 500 peso bill )lengthwise through the thumb and forefinger of a classmate. Tell your classmate to grab the peso bill as fast as possible and he/she can keep the money if he/she catches it. The length of the peso bill is 15.7 cm and the average human reaction time is about 0.20 s. Will your classmate catch the bill and keep the money?

A red train traveling at 72 km/h and a green train traveling at 144 km/h are headed toward each other along a straight, level track.When they are 950 m apart, each engineer sees the other’s train and applies the brakes.The brakes slow each train at the rate of 1.0 m/s2. Is there a collision? If so, answer yes and give the speed of the red train and the speed of the green train at impact, respectively. If not, answer no and give the separation between the trains when they stop

A woodpecker's brain is specially protected from large decelerations by tendon-like attachments inside the skull. While pecking on a tree, the woodpecker's head comes to a stop from an initial velocity of 0.600 m/s in a distance of only 2.00 mm. (a) Find the acceleration in m/s2 and in multiples of g  ⎝g = 9.80 m/s2⎞  (b) Calculate the stopping time. (c) The tendons cradling the brain stretch, making its stopping distance 4.50 mm (greater than the head and, hence, less deceleration of the brain). What is the brain's deceleration, expressed in multiples of g ?

The distance of the body travels is a function of time and a given of x(t) = 16t+8t^2 , what is the velocity of the body if the t= 3 seconds?

Suppose you throw an object from a great height, so that it reaches very nearly terminal velocity by time it hits the ground. By measuring the impact, you determine that this terminal velocity is -49 mi sec.A. Write the equation representing the velocity v(t) of the object at time t seconds given the initial velocity v0 and the fact that acceleration due to gravity 9.8 m/sec2. (Here, assume you're modeling the falling body with the differential equation dy/dt = g-kv, and use the resulting formula or v(t) found in the Tutorial. Of course, you can derive it if you'd like.)B. Determine the value of k, the "continuous percentage growth rate" from the velocity equation, by utilizing the information given concerning the terminal velocity.C. Using the value of k you derived above, at what velocity must the object be thrown upward if you want it to reach its peak height after 3 sec? Approximate your solution to three decimal places, and justify your answer.

A woodpecker’s brain is specially protected from large accelerations by tendon-like attachments inside the skull. While pecking on a tree, the woodpecker’s head comes to a stop from an initial velocity of 0.600 m/s in a distance of only 2.00 mm. (a) Find the acceleration in meters per second squared and in multiples of g, where g = 9.80 m/s2. (b) Calculate the stopping time. (c) The tendons cradling the brain stretch, making its stopping distance 4.50 mm (greater than the head and, hence, less acceleration of the brain). What is the brain’s acceleration, expressed in multiples of g?

A woodpecker’s brain is specially protected from largedecelerations by tendon-like attachments inside the skull.While pecking on a tree, the woodpecker’s head comes to astop from an initial velocity of 0.600 m/s in a distance of only2.00 mm. (a) Find the acceleration in m/s2and in multiplesof g (g= 9.80m/s2)⎠. (b) Calculate the stopping time. (c)The tendons cradling the brain stretch, making its stoppingdistance 4.50 mm (greater than the head and, hence, lessdeceleration of the brain). What is the brain’s deceleration,expressed in multiples of g ?

A person driving on I-82 glanced at his phone to read a very important text message.  When he looked back up at the road, he saw that the traffic ahead had come to a standstill and he immediately slammed on his brakes.  His car created 96.5 m long skid marks before rear-ending another car.  Unfortunately, a passenger in the rear-ended car was seriously injured, thus requiring an investigation by the State Patrol.  The State Patrol has no proof of distracted driving, however they want to determine if a citation for speeding should be issued.   A State Patrol investigator used a 3.9 kg drag sled to determine the coefficient of kinetic friction between the road and the tires of the car.  The drag sled’s spring scale read 28 N when it was pulled along the ground at a constant speed.   Use Newton’s Second Law and kinematics to estimate the minimum value of the car’s speed when the driver locked the brakes. (answer: about 83 mi/hr)   Note: You do not need the mass of the car to answer this…