Two bals collide. the diagram below shows the initial and final velocities of the bals before collision: after collision in this case m,=1.32 kg m2 = 2.35 kg 4.45 ms u 2.23 ms -1.63 ms what is the initial momentum of the system check what the final velocity of ball 2? ms to the right (enter a negative number it it is to the let) if the collsion lasts for 0.154 s what is the impuise felt by bal 12 ns (right is positive, left is negativ check what average force is experienced by ball 1 during the collision? n fright is positive, left is negative check select any of the comments below t are correct mere may be motan or co oct art. 1.00 select one or more a. momentum is conserved so this is an elastic colision c. ball 1 and ball 2 experience identical forces d. kinetic energy is conserved in this colision so the collision is elastc 6. the forces experienced by ball 1 and bal 2 have the same magnitude

Why is alternating current more effective at long–distance travel than direct current? a. the power lines are made out of conductors. b. transformers increase or decrease voltage as needed. c. the ac generator is more efficient. d. ac has lower voltage than dc.

The frequency of vibrations of a vibrating violin string is given by f = 1 2l t ρ where l is the length of the string, t is its tension, and ρ is its linear density.† (a) find the rate of change of the frequency with respect to the following. (i) the length (when t and ρ are constant) (ii) the tension (when l and ρ are constant) (iii) the linear density (when l and t are constant) (b) the pitch of a note (how high or low the note sounds) is determined by the frequency f. (the higher the frequency, the higher the pitch.) use the signs of the derivatives in part (a) to determine what happens to the pitch of a note for the following. (i) when the effective length of a string is decreased by placing a finger on the string so a shorter portion of the string vibrates df dl 0 and l is ⇒ f is ⇒ (ii) when the tension is increased by turning a tuning peg df dt 0 and t is ⇒ f is ⇒ (iii) when the linear density is increased by switching to another string df dρ 0 and ρ is ⇒ f is ⇒

If you wanted to move an electron from the positive to the negative terminal of the battery, how much work w would you need to do on the electron? enter your answer numerically in joules.