High school???
No way
It's work.
Answer:
(a) 2.5 m/s
(b) 37.5 KJ
Explanation:
(a)
From the law of conservation of momentum, Initial momentum=Final momentum
and making the subject then
and since is initial velocity of car, value given as 4 m/s, is the initial velocity of the three cars stuck together, value given as 2 m/s and is the final velocity which is unknown. By substitution
(b)
Initial kinetic energy is given by
Final kinetic energy is given by
The energy lost is given by subtracting the final kinetic energy from the initial kinetic energy hence
Energy lost=350-312.5=37.5 KJ
The answer is 18000 kgm/s
Momentum is mass times velocity so just do 750•24.
Let be the height of the building and thus the initial height of the ball. The ball's altitude at time is given by
where is the acceleration due to gravity.
The ball reaches the ground when after . Solve for :
so the building is about 16 m tall (keeping track of significant digits).
It's 12.1 m/s, assuming that's the launch velocity that's given.
For projectile motion, velocity's y-component is parabolic/quadratic. It's x-component is constant, so you don't need to know it.