The 55g arrow is launched so that it hits and embeds in a 3.54kg block. The block hangs from strings. After the arrow joins the block, they swing up so that they are 0.49m higher than the block's starting point. How fast was the arrow moving before it joined the block? THE ANSWER FOR PEOPLE WITH MASTERING PHYSICS CUZ MOST OF THEM ARE WRONG ON PE = mgh = (3.54 + 0.55)kg * 9.8m/s² * 0.49m = 17.3 J

which means the post-collision KE = 17.3 J = ½ * 3.595kg * v², and

v = 3.10 m/s

Now conserve momentum: final Σ mv = initial Σ mv

3.595kg * 3.10m/s = 0.055kg * V

V = 203 m/s ≈ 200 m/s

In which of the following cases is work being done on an object? question 2 options: pushing against a locked door carrying a box down a corridor pulling a trailer up a hill suspending a heavy weight with a strong chain

Acoyote chasing a rabbit is moving 8.00 m/s due east at one moment and 8.80 m/s due south 4.25 s later. let the x axis point due east and the y axis point due north. find the direction of the coyote's average acceleration during that time.

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 ⇒