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  1. 1(a) Let u be the initial speed of the bullet. By conservation of momentum...the force acts on the block F = 25 N 2. (a) Fall in height of the person = (30 - 2.75) m = 27.25 m Use equation...

  2. ...trolley and sand) = (100 + 100) x 1.5 kg.m/s = 300 kg.m/s Let v be the final speed of the trolley. Hence, momentum of...kg sand on it = (100 + 50)v As the other 50 kg sand fall out of the trolley, it still possesses the same speed...

  3. Let mass of small sphere be m. Since mass of sphere is proportional to the cube of its radius, mass of large sphere = m(2a/a)^2 = 8m (a) Vertical distance fell by each sphere when the large sphere touches the ground = (h - 2a) Hence, speed of each sphere u...

  4. 1. Let d be the horizontal distance travelled by the flare, and t be...2.514 m = 12.95 m (c) Consider the ball's vertical falling motion, use equation v = u + at with u = 0 m/s, a = -g(=-10 m/s^2...

  5. ... Hence, deceleration of the elevator = 4000/2000 m/s^2 = 2 m/s^2 2. Let v be the speed of the ornament and missile immediately after collision By conservation...

  6. ... answer is option B. When the vessel is in free fall , both the water and vessel travel at the same downward speed. The water cannot leak out. 8. Let m be the mass of each block Use net-force = mass x acceleration F - f...

  7. ...before leaving the bowl, and projectile motion after that Let v be the velocity of the marble when it reaches the... = mg 25/15*T2 = mg T2 = 3mg/5 Let the natural length of BP be L k(a-L...

  8. ...the conservation of energy first. Change of potential energy when the object falls from distance H (H =6400 km + radius of earth) to distnace r from earth ...

  9. ... length of A above B = L/2 Let y be the overhanging length of B above ... of mass of A and B together should fall on the edge of C Hence, taking moment...

  10. ...where g is the acceleration due to gravity, taken to be 10 m/s^2 (b) Let v be the minimum firing speed of the ball, hence, (1/2).(50)v^2 = 17500 v = square...