can somebody help with this problem please.
A car traveling 52.0 km/h is 20.6 m from a barrier when the driver slams on the brakes. The car hits the barrier 2.26 s later. (a) What is the car's constant deceleration magnitude before impact? (b) How fast is the car traveling at impact?
A car traveling 52.0 km/h is 20.6 m from a barrier when the driver slams on the brakes. The car hits the barrier 2.26 s later. (a) What is the car's constant deceleration magnitude before impact? (b) How fast is the car traveling at impact?
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52km/hr = 14.4m/s = u
t = 2.26s
s=20.6m
using s = ut +1/2at^2
20.6 = 14.4(2.26) + 1/2(2.26)^2a
20.6 = 32.54 + 2.55a
2.55a = -11.944
a = -4.68m/s^2 (constant deceleration)
using v = u + at
v = 14.4 + (-4.68)2.26
v = 3.81m/s (at impact)
t = 2.26s
s=20.6m
using s = ut +1/2at^2
20.6 = 14.4(2.26) + 1/2(2.26)^2a
20.6 = 32.54 + 2.55a
2.55a = -11.944
a = -4.68m/s^2 (constant deceleration)
using v = u + at
v = 14.4 + (-4.68)2.26
v = 3.81m/s (at impact)