Physics practice questions with scalar quantities and collissions? Define scalar
ID: 1361949 • Letter: P
Question
Physics practice questions with scalar quantities and collissions?
Define scalar quantities and vector quantities. How do you distinguish them? What are the differences? Are they added or subtracted the same way? Explain. Show simple graphical representations of A + B and A - B (A and B are completely different vectors). Define an elastic collision, and state its important characteristics. Which energies are conserved during an elastic collision (i. e. kinetic energy, total energy, or both)? Define what an inelastic collision is, clearly stating its essential properties. Which physical quantities are conserved during an inelastic collision? Define a perfectly inelastic collision, and denote its defining characteristics. Which physical quantities are conserved during a perfectly inelastic collision? Identify whether the following quantities are scalars or vectors, and which of these are always conserved: velocity; speed; momentum; total momentum; kinetic energy; potential energy; and total energy. Ball A, moving at 12 m/sec, collides elastically with Ball B, initially at rest, as shown in the figure at right. If both balls have the same mass, what is the final velocity of Ball A? Show all of your calculations. Two 1-kg carts with spring bumpers undergo a collision on a frictionless track as shown in the before and after pictures on the right. What is the value of the total momentum of the system before and after the collision? Explain your reasoning as to why it has these values.Explanation / Answer
1b)
m1 = m2 = m
u1x = 12*sin60 = 6sqrt3 u2x = 0
u1y = -12*cos60 = -6 u2y = 0
after collision
V1x = 0 v1y = v1
v2x = V2 v2y = 0
along horizantal
Pix = Pfx
m1*u1x + m2*u2x = m1*v1x + m2*v2x
6*sqrt3 = v2x
along y
m1*u1y + m2*u2y = m1*v1y + m2*v2y
-6 + 0 = v1y
v1 = sqrt(v1x^2 + v1y^2)
v1 = 6 m/s <<-------answer
m1 = 1 m2 = 1 kg
u1 = +4m/s u2 = -4 m/s
iniital momentu Pi = m1*u1 + m2*u2 = (1*4) - (1*4) = 0
v1 = -4 m/s v2 = +4 m/s
final momentum Pf = (m1*v1) + (m2*v2)
Pf = -(1*4)+(1*4) = 0