Today's lesson .
1. Dynamics: Projectile motion in Holiday practice 2
Q12. Initial velocity is zero vertically if an object is projected horizontally.This simplifies the equation of motion to s = 0.5at*2 and v*2= 2as and v = at. The time taken can be found easily as s= 0.4m ( which is 1.6m - 1.4m) giving t =0.29s. Horizontaly, velocity can be found by dividing distance by time taken giving 6.9 ms*-1. The final velocity it hit the ground consist of horizontal and vertial component. Using pythagoras theorem the velocity is 7.4 ms*-1 at an angle of 22degrees.
