Question #774be

2 Answers
Jul 27, 2017

a) It does not come to a halt
b) #V_(fi n al)#=1.88 #m*s^(-1)#

Explanation:

a)
#p_i#=15600 #N*s#

#impu lse#= #(860*16 ) N*s^(1)#

#impu lse#= #13760 N*s^(1)#

Therefore, the car won't stop.

b)

#p_( n et)# = 15600-13760
#p_( n et)# = # 1840 N*s^(1) #
#m# = 980 kg

#v_f = (p_(n et))/m#

#v_f = 1840/980 #

#v_f = 1.88 m*s^(-1) #

Jul 27, 2017

(a) No
(b) #1.88ms^-1#, rounded to two decimal places.

Explanation:

Momentum of car #|vecp|=15600Ns#
Mass of car #=980kg#
Velocity of car #=|vecp|/m=15600/980=780/49ms^-1#

Stopping force applied #=860N#
(it is assumed that it is applied against the direction of initial momentum)
Retardation#=|vecF|/m=860/980=43/49ms^-2#

using the kinematic expression

#v=u+at#

final velocity after #16s#
#v=780/49+(-43/49xx16)#
#v=780/49-688/49#
#v=1.88ms^-1#, rounded to two decimal places.