Question

8) A particle initially at rest accelerates at 5.0 m/s2. How fast is it moving after 3.2 s? How far 9) A car is moving at 12.0 m/s and then accelerates at 1.5 m/s2 for 10 seconds. What is the 10) A bal is dropped from height H and accelerates downward with acceleration g. In terms of H 11) A rock is thrown straight up in the air at 6.2 m/s and it is released 1.8 m above the ground. will it travel in 4.0 s? How long will it take to travel 100.0 m? velocity after 10 seconds? How far did the car travel during this time? and g, solve for the time it takes to hit the ground. Write an equation of motion to describe the height of the rock relative to the ground. (neglect air resistance and use g 9.8 m/s2)

Answer 1

v = u + at v = 0 + 5 times 3.2 v = 16 m/s S = ut + 1/2 at^2 S = 0 + 1/2 times 5 times 16 S = 40 m S = ut + 1/2 at^2 100.0 = 0 + 1/2 times 5 times t^2 t^2 = 40 rightdoublearrow t = 6.32 s u = 12.0 m/s t = 10 sc a = 1.5 m/s^2 v = u + at v = 12 + 1.5 times 10 v = 27.0 m/s S = ut + 1/2 at^2 S = 12 times 10 + 1/2 times 1.5 times 100 S = 195 m S = ut + 1/2 at^2 H = 0 + 1/2 gt^2 t = squareroot 2H/g Initially it go up and then reaches the groud h = 1/2 gt^2 - ut 1.8 = 1/2 times 9.8 times t^2 - 6.2t 4.9t^2 - 6.2t = 1.8 Solving t = 1.51 sec In 1.51 sec it reaches ground