We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive pseudonymised information about your use of our website. cookie policy and privacy policy.

1) the flight speed of a small bottle rocket can vary greatly, depending on how well its powder burns. Suppose a rocket is launched from rest so that it travels 12.4 m upwards in 2 s. What is the rocket's net acceleration?


2) The shark can accelerate to a speed of 32 km/h in a few seconds. Assume that it takes a shark 1.5 s to accelerate uniformly from 2.8 km/h to 32 km/h. What is the magnitude of the shark's acceleration?


3) In order for the Wright brothers in 1903 flyer to reach launch speed it had to be accelerated uniformly along a track that was 18.3 m long. A system of pulleys and falling weights provided acceleration. If the flyer was initially at rest and it took 2.74 s for the flyer to travel the lenght of the track what was the magnitude of its acceleration? 


4) A roller coaster increases the speed of its cars as it raises them to the top of the incline. Suppose the cars move at 2.3 m/s at the base of the incline and are moving at 46.7 m/s at the top of the incline. What is the magnitude of the net acceleration if it is uniform acceleration and takes place in 7 s?


5) A ship with an initial speed of 6.23 m/s approaches a dock that is 255 m away. If the ship accelerates uniformly and comes to rest in 82 s, what is its acceleration?

 Feb 15, 2019

1) \(d={v_0t}+\frac{1}{2}at^2\\ a_{rocket}=\frac{2d}{t^2}=\frac{2*12.4m}{(2s)^2}=6.2\;m/s^2\)

2)\(a=\frac{\Delta v}{\Delta t}=\frac{32\;km/h\;-\;2.8\;km/h}{1.5s}=\frac{29.2\;km/h}{1.5s}\\ \text{Use dimensional analysis to convert to m/s}^2\\ \frac{29.2\;km/h}{1.5s}*\frac{1h}{3600s}*\frac{1000m}{1km}\approx5.41\;m/s^2\) 


3) \(d=v_0t+\frac{1}{2}at^2\\ a=\frac{2d}{t^2}=\frac{2*18.3m}{(2.74s)^2}\approx4.88\;m/s^2\)


4)\(v=v_0+at\\ a=\frac{v-v_0}{t}=\frac{46.7m/s\;-\;2.3m/s}{7s}\approx6.34\;m/s^2\)


5)\(v=v_0+at\\ a=\frac{v-v_0}{t}=\frac{0-6.23m/s}{82s}\approx-0.076\;m/s^2\)

 Feb 15, 2019

33 Online Users