Part-I: Answer the following 10 multiple choice questions: (10 x 6 60 pts) 1. Wh
ID: 1650921 • Letter: P
Question
Part-I: Answer the following 10 multiple choice questions: (10 x 6 60 pts) 1. When can we be certain that the average velocity of an object is always equal to its instantaneous velocity? A) always B) never C) only when the velocity is constant D) only when the acceleration is constant Ans: 2. The displacement can be A) positive B) negative C) both positive and negative D) none Ans. 3. The value of an object's acceleration may be characterized in equivalent words by which of the following? A) displacement B) rate of change of displacement C) velocity D) rate of change of velocity Ans: 4. The motion of a particle is described in the velocity versus time graph shown in the figure.Explanation / Answer
1)
If the object moves with constant velocity, then the
velocity is same at every point
average velocity = instantaneous velocity
OPTION C <<<<--------answer
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2)
displacement dx = xf - xi
x can be either positive or negative
so diplacement can be either positive or negative
OPTION (C)
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3)
acceleration is defined as rate of change in velocity
OPTION (D)
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4)
slope of the graph gives acceleration
In the graph slope is constant and positive
acceleration has positive value
acceleration a = (vf- vi)/dt
Initially the particle is moving in negative direction
the speed decreased to 0 and then increased in positive direction
OPTION (D)
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5)
velocity is vector . so it can be positive or negative
OPTION (C)
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6)
acceleration a = (v2 - v1)/t
acceleration is positive, the speed is increasing
acceleration is negative it is called deceleartion , the speed is decreasing
OPTION (B) and (A)
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7)
g = 9.8 m/s^2
OPTION (C)
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8)
velocity is defined as rate of change in velocity
OPTION (D)
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9)
acceleration = rate of change in velocity
At point A and C the direction is changing so the object has acceleration
at point C the speed and direction is constant
so the velocity is constant
acceleration is zero
OPTION (B)
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10)
cm/s2
OPTION (D)