Trincomalee Campus of the Eastern University of Sri Lanka Department of Physical Science, Faculty of Applied Science Year I Semester I (2019/2020) General Physics I CA -2

 Trincomalee Campus of the Eastern University of Sri Lanka 

Department of Physical Science, Faculty of Applied Science 

Year I Semester I (2019/2020) 

General Physics I 

CA -2

Part I 

1) A horizontal force of 95.0 N is applied to a 60.0-kg crate on a rough, level surface. If the crate accelerates at 1.20 m/s2, what is the magnitude of the force of kinetic friction acting on the crate? 

 (a) 23.0 N            (b) 45.0 N          (c) 16.0 N         (d) 33.0 N          (e) 8.80 N 

2) As a block slides down a frictionless incline, w hich of the following statements is true? 

 (a) Both its speed and acceleration increase.                (b) Its speed and acceleration remain constant.   (c) Its speed increases and its acceleration remains constant.                                                                   (d) Both its speed and acceleration decrease.         (e) Its speed increases and its acceleration decreases.

 3) If Earth’s mass and radius both suddenly doubled, what would be the new value of the acceleration of gravity near Earth’s surface?

  (a) 9.80 m/s2       (b) 4.90 m/s2      (c) 2.45 m/s2   (d) 19.6 m/s2     (e) 12.6 m/s2 

4) Four forces act on an object, given by 𝐴⃗ = 40 N east, 𝐵⃗⃗ = 50 N north, 𝐴⃗ = 70 N west, and 𝐷⃗⃗ = 90 N south. What is the magnitude of the net force on the object? 

  (a) 50 N               (b) 70 N             (c) 131 N          (d) 170 N           (e) 250 N 

Part II  

1) A 800 kg car starts from rest on a horizontal roadway and accelerates eastward for 5 s when it reaches a speed of 25.0 m/s. What is the average force exerted on the car during this time? 

2) Two objects with masses of 3.00 kg and 5.00 kg are connected by a light string that passes over a frictionless pulley, as in Figure. Determine 

     i. the tension in the string, 

    ii. the acceleration of each object, and 

   iii. the distance each object will move in the two seconds of motion if both objects start from rest. 

3) A block of mass m1 = 5 kg and a ball of mass m2 = 10 kg are connected by a light string that passes over a frictionless pulley, as shown in Figure 2. 

The coefficient of kinetic friction between the block and the flat surface is 0.5. Find the acceleration of the two objects and the tension in the string.

Year I Semester I- 2019/2020 General Physics I _Continuous Assessment I_Trincomalee Campus, Eastern University of Srilanka Department of Physical Science, Faculty of Applied Science

 Trincomalee Campus, Eastern University of Srilanka 

Department of Physical Science, Faculty of Applied Science 

Year I Semester I- 2018/2019 

General Physics I 

 Continuous Assessment I

1) Write down the most useful three fundamental equations that describe the motion of an object moving with constant acceleration along one dimensional.

 2) A rocket moves straight upward, starting from rest with an acceleration of 30 m/s2 . It runs out of fuel at the end of 4.00 s and continues to coast upward, reaching a maximum height before falling back to Earth. 

            (i) Find the rocket’s velocity and position at the end of 4.00 s. 

            (ii) find the maximum height the rocket reaches and 

           (iii) find the velocity the instant before the rocket crashes on the ground. 

3) A student stands at the edge of a building and throws a stone horizontally over the edge with a speed of 18.0 m/s. The building is 50.0 m above a flat, horizontal beach as shown in following Figure

           i. Find the x- and y-components of the initial velocity;

          ii. Write the equations for the x- and y-components of the velocity of the stone with                time; 

           iii. How long after being released does the stone strike the beach below the cliff?; 

           iv. With what speed and angle of impact does the stone land?.

4) If a stone is thrown upward from the top of the building at an angle of 30° to the horizontal with the initial velocity of 20 m/s Find:

          i. the velocity of stone at impact;

        ii. the horizontal range of the stone; 

       iii. time taken for the stone to hit the ground