- #1
Keeptrying83
- 1
- 0
Homework Statement
You are traveling on a bike, moving at a constant speed of 20,0 km/h. You just finished eating an apple, and you wish to pop the core into a trash bin located by a busstop.The bin is 3,00 m from the edge of the road (where you are biking). You throw it at a point 4,00 m before you pass the trash bin. The apple core behaves as a projectile under the force of gravity g = 9,80 m/s^2, and you can ignore friction and wind. The height of the (top of the) bin is the same as the height of your hand as you throw, 1,00
m above the ground.
a) You throw the apple upwards at an angle of = 20 degrees with horizontal. With what initial velocity vector relative to the Earth should you throw the apple to hit the bin?
b) With what initial velocity vector relative to you and the bike should you throw the apple to hit the bin? What speed does that correspond to?
c) As it happens, a little old lady is standing exactly halfway between you and the bin. She is 160 cm tall. Do you hit her? Remember to draw a sketch of the situation.
Homework Equations
For (a) I used the range equation, R=(v^2 * sin(thetha))/g
The Attempt at a Solution
For (a) I used the range equation R=(v^2 * sin(thetha))/g and got 8,73 m/s.
In (b) I struggle with getting started. If the bike relative to the Earth is the velocity vector in y-direction (20 km/h), and the the apple relative to Earth is the second vector. Then the velocity vector for me relative to the bike is the opposite vector from the angle? I am really stuck on this one, hope someone can help me here:)