Engineering Mechanics Dynamics Home Work-1017
Page.65
12-113. The position of a particle is defined by r = {4(t-sin t) i + (2t2-3) j} m,
where t is in seconds and the argument for the sine is in radians. Determine the speed
of the particle and its normal and tangential components of acceleration when t = 1 s.
Ans: υ =4.40m/s, at =5.04m/s2, an =1.39m/s2
Page.66
12-122. The car travels along the circular path such that its speed is increased by
at = (0.5et) m/s2, where t is in seconds. Determine the magnitudes of its velocity and
acceleration after the car has traveled s = 18m starting from rest. Neglect the size of
the car.
Ans: υ =19.9m/s, a =24.2m/s2
Page.68
12-130.
Ans: a =32.2m/s2
12-135.
Ans: υ =1.96m/s, a =0.930m/s2
Page.98
12-195.
Ans: υB =1.67m/s
Page.99
12-202.
Ans: υB =1.50m/s
Page.101
12-217.
1
Ans: υA/B =13.4m/s, θυ =31.7
。
aB/A =4.32m/s2, θa =79.0。
Page.103
12-229.
Ans:υA/B =20.5m/s, θυ =43.1。
aB/A =4.92m/s2, θa =6.04。
2