ليلة امتحان 1ث.pdf

1- A body of mass 0.01 Kg moves in a horizontal circular path of radius 150 cm. If the body makes one revolution in 3 s , the centripetal force is ……… 0.066 N in a direction tangent to the circular path 6.585 N in a direction tangent to the circular path 0.066 N towards the...

1- A body of mass 0.01 Kg moves in a horizontal circular path of radius 150 cm. If the body makes one revolution in 3 s , the centripetal force is ……… 0.066 N in a direction tangent to the circular path 6.585 N in a direction tangent to the circular path 0.066 N towards the center of the circular path 6.585 N towards the center of the circular path 2- If a body moves in a uniform circular path with constant tangential velocity of 2.2 m/s where it completes 6 revolutions in a minute , then the radius of the path equals ……… 3.5 m 7m 10.5 m 12 m 3- A body of mass 0.1 Kg is moving in a uniform horizontal circular path with a speed of 2 m/s , so the magnitude of change in its momentum after completing half a revolution equals …… zero 0.2 Kg.m/s 0.4 Kg.m/s 0.8 Kg.m/s 4- If a stone that is attached to a thread of length 0.4 m is whirled in a horizontal plane with a periodic time of 0.2 s , its centripetal acceleration equals ……… m/s2 20 π2 40 π2 2 π2 8 π2 5- A washing machine has a centripetal acceleration of 4302 m/s2 and a radius of 20 cm then it completes 7000 revolutions through ……….. 1 minute 3 minutes 5 minutes 7 minutes 6- Body A moves in a horizontal path of radius rA and body B moves in a horizontal circular path of radius rB where the two bodies move with the same speed. If the 𝑻 𝟏 two bodies are identical and the ratio between their periodic times ( 𝑨 ) is , so 𝑻𝑩 𝟐 𝑭𝑨 the ratio between their centripetal forces ( ) is …… 𝑭𝑩 𝟐 𝟏 𝟏 𝟏 𝟏 𝟏 𝟐 𝟖 7- The ratio between the orbital radii of two satellites rotating around a planet are 3 : 2 if the periodic time of the second satellite is 8 × 107 s , then the periodic time of the first equals ……… 5 × 105 s 1.5 × 108 s 2.3 × 108 s 4.5 × 108 s 8- If R is the radius of the Earth , the height at which the weight of a body becomes 𝟏 its weight on the surface of the Earth is ……… 𝟒 𝑹 𝑹 2R R 𝟐 𝟒 9- An object of mass 0.5 Kg at rest , started to fall from a height of 180 cm above the ground. Its momentum when it reaches the ground will be ……… (g = 10 m/s2) 3 Kg.m/s 5 Kg.m/s 6 Kg.m/s 9 Kg.m/s MR: Ahmed Hakki 1 secondary  10- The following figures represent four cases of a body that moves under the effect of a force F in the directions shown in the figures , in which of the following cases theFwork done on the body is the largest ? F F F d θ d θ d d 1 θ2 11- A car moves in a circular path of radius 10 m. If the tangential velocity of the car is 30 m/s , what is the car's acceleration ? 3 m/s2 towards the center 90 m/s2 away from the center 90 m/s2 towards the center 270 m/s2 towards the center 12- An object of mass 0.5 Kg at rest , started to fall from a height of 180 cm above the ground. Its momentum when it reaches the ground is ……… ( g = 10 m/s2) 3 Kg.m/s 5 Kg.m/s 6 Kg.m/s 9 Kg.m/s 13- Two bodies x and y have same mass , if (K.E)x = 4 (K.E)y , then the momentum of body x (px) equals ………… py 2 py 4 py 8 py 14- An object is projected vertically upwards with a velocity of 20 m/s from the top of a building of height 15 m. So , the object's kinetic energy equals its potential energy at a height of ……… above the ground (Take : g = 10 m/s2) 7.5 m 15 m 17.5 m 35 m 15- Which of the following graphs does not express a body that is projected vertically upwards till it reaches the maximum height ? P.E K.E E K.E h t t P.E 16- The potential energy of a body at the top of a building was 200 J , so if this body undergoes a free fall from the top of the building , its mechanical energy at the midpoint of the building height equals ……… 100 J 200 J 400 J 600 J 17- The opposite figure shows a ball sliding from A C rest at point A on a smooth curve , so if the speed of the ball at point C is 8 m/s , the height 12.8 h of point C above the ground equals ……… m ( g = 10 m/s2) 6.8 m 7.2 m 8.8 m 9.6 m MR: Ahmed Hakki 1 secondary  18- The opposite graph represents the relation between the momentum (P) and the velocity (v) P(Kg.m/s) for two cars A , B which are moving in a straight A line , hence which of the following choices is correct ? B The mass of car A equals the mass of car B The mass of car A is less than the mass of car B V(m/s) The mass of car A is greater than the mass of car B The answer can't be determined 19- A car is moving on a curved road of radius r , banked with an angle 𝛉 with the horizontal plane , hence by increasing the value of angle 𝛉 , ……… the vertical component of car's weight increases the horizontal component of the frictional force increases the horizontal component of the reaction force increases the vertical component of the reaction force increases 20- The opposite (displacement – time) graph describes d(m) the motion of a body of mass 10 Kg , so the kinetic energy of this body equals …………. 15 25 J 50 J 125 J 225 J 3 t(s) 21- The opposite graph represents the relation between the P.E potential energy (P.E) of two bodies (A and B) and the height A (h) at which they are placed above the ground , the ratio 𝑾𝑨 B between the weights of the two bodies ( ) equals …… 30o 𝑾𝑩 𝟐 𝟏 30o h 𝟏 𝟐 𝟏 𝟑 𝟑 𝟏 22- A child of mass 40 Kg moves horizontally on a skating surface , then the work done by his weight when he moves a distance of 20 m is …………. Zero 800 J 4000 J 8000 J MR: Ahmed Hakki 1 secondary