Cars P and Q start the journey from the stationary at the same time and each accelerates with the acceleration # a # and #3ms ^ - 2#. After 2 seconds, P leads Q by 6 m. Find # a #?

Question

A # 4.5ms ^ (- 2) #
B # 5.0ms ^ (- 2) #
C # 5.5ms ^ (- 2) #
D # 6.0ms ^ (- 2) #

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Answer 1 · 2018-07-28T10:23:51

D. #6ms^-2#

Distance #d =V_0t + 1/2at^2#

Car P has acceleration #a#
Car Q has acceleration #3ms^(-2)#
#V_0 = 0 # for both cars
#t = 2s#

Distance traveled by car Q:
#d_Q = 0*t + 1/2 * 3 *(2^2) = 6#m

Distance traveled by car P:
#d_P = 0*t + 1/2 * a *(2^2) = 6+6 = 12#m

#4/2*a = 12#

#a = 12*2/4 = 6ms^-2#