Projectile motion help please (1 Viewer)

[zb123]

Can someone please help with projectile motion:
Cambridge 3 unit book Ex 3G, question 10c

If someone has the book can you PLEASE explain it, and if you can, also question 12

 

[fortune_cookie]

tan(a)= 2/5

From this,

sin(a) = 2/sqrt(29) , cos(a) = 5/sqrt(29)

Then set up a new set of equations (it's best to assume the new origin at the point where the ball touches the wall).

x= - vt cos(a) = - (0.2 x 5sqrt(58)) t [5/sqrt(29) ] = -12.5tsqrt(2)

y= vtsin(a) - (1/2)gt^2 = (0.2 x 5sqrt(58) )t [2/sqrt(29)] - (1/2) (10) t^2 = 2sqrt(2)t - 5t^2

Now, solve for t when y= -52.5. Then sub that value for t into the equation for x. Then add 75m to that value of x.

 

[zb123]

Thankyou~!