Welcome to your PHYSICS GRADE 12 MODEL EXAM 2017
PHYSICS MODEL EXAMINATION FOR GRADE 12
2017 E.C
1.
If the tail of vector B is placed at the tip of A and the tail of C is placed at the tip of B, the sum of the three vectors is drawn from the:
2.
Which one of the following is not correct aboutthe difference between distance and displacement?
3.
A 25.0 kg block is initially at rest on a horizontal surface. A horizontal force of 75.0 N is required to set the block in motion. After it is in motion, a horizontal force of 60.0 N is required to keep the block moving with constant speed. Find the coefficients of static and kinetic friction from this information respectively (g=10m/s²)
4.
Which one of the vector diagrams satisfies the vector equation C = A + B?
5.
Which one is not true about action and reaction forces?
6.
A net force F₁ acting on a mass m causes an acceleration a when the force tripled the acceleration increased by 6. What will be the new acceleration acting on the same mass?
7.
The magnitude of vector A is half of the magnitude of vector B when they act parallel to each other, they yield a resultant of 90 units. The magnitude of vector A & B respectively
8.
In the Atwood machine, shown on the diagram, two masses M and m are suspended from the pulley, what is the magnitude of the acceleration of the system? (Ignore friction and the mass of the pulley, M > m) Use (m=6kg, M=9Kg)
9.
An object moving with a constant acceleration covers 60m in 4 seconds and 20m during the 4th second. What are the magnitude of acceleration and initial velocity during this motion respectively?
10.
Which one of the following is not necessarily true?
11.
What is the work done by a force F = 20N (0.6i + 0.8j) in moving an object through a displacement of S = 4m (2i + j)?
12.
The length of the train is 50m and its front is 200m from a pole. The train accelerates at 4m/s². At what speed does its front and rear pass the pole if it starts from rest respectively?
13.
A cosmic body of extremely intensive gravity from which nothing, not even light can escape is
14.
The system we can apply for security lock in banking system to keep information secret from hackers and cyber-attacks is-
15.
From the given graph below, the body accelerated by 3m/s² in the first 10 seconds and moves with constant velocity from 10 to 50 seconds and then decelerated by 5m/s² from 50 to t seconds. What will be the acceleration between 10 to 50 seconds?
16.
Based on question no. 15 above, what is the total distance of the graph?
17.
Which of the following cannot be possible for the graphs of uniformly accelerated motion?
18.
A man is weighing a fish mass m using a spring balance attached to a ceiling of an elevator, which one of the following statements is wrong about the reading of the balance?
19.
A rectangular block weighs 600N and has sides 3m by 2m and 4m as shown in the figure and placed on a surface. What is the minimum pressure the box exerts on the surface?
20.
What is the total pressure on a diver in a sea at a depth of 30m below the surface? The density of sea water is ρ=1020Kg/m³ and Patm=100,000Pa, g=10m/s²
21.
The smaller piston in a hydraulic press has an area of 100cm² while the larger piston has an area of 400cm². What is the force exerted on the smaller piston in order to support a load of 100N on the larger piston?
22.
All are among the relationship of physics with biology except:
23.
Which of the following is false?
24.
Which of the three holes A, B, and C in the container of shown in the figure has the least pressure?
25.
Sharper knives are effective in cutting. This is due to:
26.
Two balls are thrown with the same speed but making complementary angles with the horizontal. If the angle of one of the projections is 30° and its maximum height is h, then the maximum height of the other will be: (sin 30° = 0.5, cos 30° = √3/2)
27.
A block of mass 2kg is being pulled along a board horizontally with a constant velocity. The coefficient of friction between the board and the block is 0.2. Then the friction force acting on the block is (g=10m/s²)
28.
What is the final angular velocity when the initial angular velocity is 5rad/sec, the angular acceleration is 2rad/sec², and the time of motion is 10sec?
29.
The gravitational force between two objects is 8x10⁻⁹N when they are 3cm apart. For what separation would the force between the two objects for the same mass be 6x10⁻⁹N?
30.
Which of the following is true about Kepler’s law of planetary motion?
31.
Which of the following is false?
32.
What kind of systems do mechanical engineers create using concepts like dynamics and forces?
33.
A 5kg block is supported by two strings that are tied to rigid supports as shown in the figure below. If the body is in equilibrium, then what is the size of the tension force on each string? (Cos 37° = sin 53° = 0.8, sin 37° = cos 53° = 0.6, g = 10m/s²)
34.
Which of the following statements is correct?
35.
An engineer wanted to put a speed limit at the entrance to a train at 300m away as it comes to rest to the platform. His plan is to give exactly 1.5 minutes for the train to decelerate uniformly within the 300m distance. What must the maximum speed at the entrance?
36.
A ball of mass 2Kg is rolling at a velocity of 10m/s on a horizontal frictionless surface collides with another ball of mass 3kg at rest and locked bumper. What is the common velocity of the balls after the collision?
37.
Two cars A and B are moving along a straight road in the same direction. The relative velocity of car B with respect to car A is 10m/s. If the velocity of car B is 60Km/h with respect to the ground, what is the velocity of car A?
38.
In which of the following cases do you think that work is done in physics?
39.
Which one of the following cannot be the resultant when 10N and 30N are added by vector addition rule?
40.
A body accelerates from 10m/s to 20m/s having a mass of 40kg. What will be the magnitude of the work done? (ignore friction)
41.
Two blocks of identical materials are connected by a light string on a level surface in the given figure below. Assuming no friction between the blocks and the level surface, find the acceleration of the masses in the connecting string when the string attached to M₁ is pulled to the right by a 36 N force. (Use M₁ = 4 kg and M₂ = 8 kg.)
42.
A girl and a boy are given similar work to complete in a certain time. If a girl completes half of the time than the boy, which of the following is true?
43.
A body moving with constant acceleration covers a distance between two points 90m apart in 6 seconds. Its velocity as it passes the second point is 18m/s. What is the acceleration of the body?
44.
Which one of the following is correct about the four basic forces in nature?
45.
The unit vector in the direction of A = 3i + 4j is ______
46.
A driver moving at a constant speed of 20m/s sees an accident up ahead and hits the brakes. If the car decelerates at a constant rate of 5m/s², how far does the car go before it comes to stop?
47.
A projectile is fired at an angle of 53° with the horizontal. If the initial velocity of the projectile is 10m/s, what is the maximum height of the projectile? (use sin 53° = 0.8, cos 53° = 0.6)
48.
A body is thrown vertically upward and at the instant when it reaches its maximum height:
49.
If two Balls X and Y have different masses Mx = 3My and they are dropped from the same height above the ground at the same time, which one of them reaches the ground first?
50.
If the dot product of two vectors is equal to zero, then what do we know about the two vectors?
