Kinematics - 11-12

Question

4. A projectile shot at an angle 60 degree to the horizontal, strikes a wall 30m away at a point 15m above the point of projection.(g=10m/s^2)
(a) Find the speed of projection.
(b) Find the magnitude of velocity of the projectile when it strikes the wall.

6. Two particles move near surface of earth with uniform acceleration g=10m/s^2 towards the ground. At the initial moment, the particles were located at one point in space and moved with velocities v₁=3.0 m/s and v₂=4.0 m/s horizontally in opposite directions. Find the distance between the particles at the moment when their velocity vectors becomme mutually perpendicular.

Can anyone provide solution for all the questions in the image

Answer 1

The solution for question 4:

Using the formula y=xtanθ-gx²/(2u²cos²θ)

here y= 15m, x=30 m

θ=60

then calculate u

u=21.85 m/s

Magnitude of the velocity when it hit the wall can be calculated as

v²=u²-2gh

  =(21.85)²-2*9.81*15

v=13.53 m/s

Solution for question 6: