A baseball is hit directly upward with an initial speed of 42 m/s. Find the velo

Question

A baseball is hit directly upward with an initial speed of 42 m/s. Find the velocity of the ball when it is at a height of 45 m.

Is there one correct answer for v or two?

onetwo     

Explain why.

a.)Since the solution for velocity involves a square root we do get two answers. Only one of these answers has physical meaning.

b.)Since the solution for velocity does not involve a square root we do not get two answers.     

c.)Since the solution for velocity involves a square root we do get two answers. Both of these answers have physical meaning.

Explanation / Answer

ui=42 m/s

a=g=-9.8 m/s2

v2-u2=2as

v2=u2+2as=422-2*9.8*45=882

v=29.6984 m/s or v=-29.6984

the answer is c.it has 2 value with 2 physical meaning.both signs represent different direction of velocity.+29.6984 m/s is when body moves upward while -29.6984 m/s is achieved by body when it moves downward after reaching maximum height.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.