lecture14_clicker

# lecture14_clicker - save her by catching her with his...

This preview shows pages 1–4. Sign up to view the full content.

A pitcher throws a 0.15-kg baseball so that it crosses home plate horizontally with a speed of 20 m/s. The ball is hit straight back at the pitcher with a final speed of 22 m/s. What is the impulse delivered to the ball? A. 0.30 kg m/s towards pitcher B. 0.30 kg m/s toward batter C. 6.3 kg m/s toward pitcher D. 6.3 kg m/s toward batter I = P f –P i = m(V f -V i ) = 0.15 (-22 – 20) kg m/s = -6.3 kg m/s Negative means toward pitcher p I r r =

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Find the average force exerted by the bat on the ball if the two are in contact for 2.0 × 10 –3 s. A. 3.1 × 10 3 N towards pitcher B. 3.1 × 10 3 N towards batter C. 6.3 N towards batter D. 6.3 N towards pitcher From last page: impulse delivered to the ball = - 6.3 kg m/s I = F t F = I/ t = -6.3/0.002 N
Mary Jane falls from a tower. Spiderman tries to

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: save her by catching her with his webbing. By the time that the webbing reaches Mary Jane, she is falling at 40 m/s. If the mass of Mary Jane is 50 kg and the webbing stops her motion in 0.5 second, what is the net force on her during this interval? = 50*(0-(-40))/0.5 = 4000 N Quiz (will count for credit) A. 500 N B. 4000 N C. 400 N D. 500 N E. 2000 N t p F ∆ ∆ = r r Two objects collide head on. Their masses and initial velocities are given. If the 10 kg mass has a final velocity of -0.1 m/s, what is the final velocity of the 1 kg mass? 10 kg 1 m/s 1 kg-1 m/s 10 kg-0.1 m/s 1 kg ? m/s A.-10 m/s B.-1 m/s C. 0.1 m/s D. 10 m/s m 1 v 1i + m 2 v 2i = m 1 v 1f + m 2 v 2f 10 (1) + 1 (-1) = 10 (-0.1) +1 v 2f...
View Full Document

{[ snackBarMessage ]}

### Page1 / 4

lecture14_clicker - save her by catching her with his...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online