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.