20 Physics -- Kinematics

1. Figure 3.64 shows the position-time graphs of three cars A, B, and C. On the basis of the graphs, answer the following questions:i) Which car has the highest speed and which is the lowest?ii) Are the three cars ever at the same point on the road?iii) When A passes C, Where is B?iv)...

1. Figure 3.64 shows the position-time graphs of three cars A, B, and C. On the basis of the graphs, answer the following questions:

i) Which car has the highest speed and which is the lowest?

ii) Are the three cars ever at the same point on the road?

iii) When A passes C, Where is B?

iv) How far did Car A travel between the time it passed cars B and C?

v) What is the relative velocity of Car C with respect to car A?

vi) What is the relative velocity of car B with respect to car C?

1 Answers

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Solution

Velocity of car A = slope of x-t of A = 14-6/1.6 = 5km/hs

Velocity of car B = slope of x-t of B =14-0/1.4 = 10km/hs

Velocity of car C = slope of x-t of c = 14-2/1 =12km/hs

A) Car C has the highest speed and car A has the lowest.

B) There is no point where all three line intersect. so, all three car never meet at a same position.

C) When car A passes car C, car B is at 6km.

D) Time interval= 1.2-0.6 = 0.6hr

E) Relative velocity of Car C with respect to car A(v_CA)=V_C-V_A =12-5 =7km/hr

F) Relative velocity of Car B with respect to car C(v_BC)= V_B - V_C = 10-12 = -2km/hr

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