Impulse problem (intro mechanics)

[acherentia]

Homework Statement

A rubber ball (mass 0.26 kg) is dropped from a height of 1.7 m onto the floor. Just after bouncing from the floor, the ball has a speed of 3.6 m/s.
(a) What is the magnitude and direction of the impulse imparted by the floor to the ball? Magnitude ? kg · m/s

(b) If the average force of the floor on the ball is 17 N, how long is the ball in contact with the floor?

Homework Equations

dp=Fdt=m(vf-vi)

The Attempt at a Solution

a)the unknown is the initial speed of the dropping ball under free fall:

v_i= sqrt (2 x 9.8 x 1.7) = 5.8

delta p= 0.26 (3.6--5.8)=2.4

b) dt=dp/F_ave=0.14 s

Please let me know what is wrong here, my electronic assignment system is telling me the numbers are wrong. Thank you!

 

[ideasrule]

Your answers all seem right to me.

 

[kerimek]

Your calculations seem correct. However, there may be a discrepancy with the given values. Please double check the values provided for the initial and final speeds of the ball, as well as the average force of the floor. Also, make sure to use consistent units throughout your calculations. If the issue persists, it would be best to consult with your instructor for further clarification.