Physics Final Exam Terhona

Physics Final Exam ( First Term) Date : 25-6-2009

(Time : Three Hours )

Q1) 12 points     a -Two vectors A and B are given by A = 5 iˆ + 6 ˆj + 7 kˆ and B = 3 iˆ – 8 ˆj + 2 kˆ . If these two vectors are drawn starting at the same point, what is the angle between them ? b - A block is pulled along a level frictionless surface by a ( 20 N ) horizontal force , What is the acceleration of the block ? if the normal force acting on it is ( n = 9.7 N ). Q2 )

12 points

a- A (2 kg) mass has (60 J ) of potential energy with respect to the ground. How far is it located above the ground? b- The heart Push with each pulse ( 80 cm 3 ) of blood from the ventricle to the aorta with velocity ( 35 cm / s ) . Find the amount of momentum of the Paid blood. -----------------------------------------------------------------------------------------------------Q3 ) 12 points a- If the aorta diameter was about ( 2 cm ) ، and the rate of blood flow approximate ) 5 Liter / min ) . Show that the average speed of blood in it is ( 26.54 cm/s ) . b- Find minimum force must be made by a nurse on the piston area of (2 cm) to push the medicine from the patient vessel in which blood pressure( 16 mm Hg) . ----------------------------------------------------------------------------------------------------Q4 ) 12 points a- Find the deference in blood pressure between the feet and the head in a person ( 1.6 m) tall. The density of blood is ( 1060 kg/m3). Why is your blood pressure measured on your upper arm? b- Manometer is used to measure the pressure of the lungs. If the person breathed in one of arms Manometer even became the difference in pressure between the surface of water ( 64 cm). Find the pressure of the lungs. Q5 ) 12 points a - Calculate the heat needed to change (200 grams) of water at ( 40 oC) to steam at (100oC). The heat of vaporization of water is 2.257 × 10 6 J / kg , (

(

)

c = 4186 J / kg oC )

b- If the piston diameter was the largest of the dentist's chair six times smaller piston diameter . Find the amount of force necessary to lift person has mass ( 80 kg), assuming that the mass of the chair ( 30 kg ) .

GOOD LUCK

Dr. Maan A. Ibrahim