Physics

2. Two stores sell pumpkins. At the first store the pumpkins weigh an average of 22 Lbs. with a standard deviation of 2.5 Lbs. At the second store the pumpkins weight an average of 18 Lbs. with a standard deviation of 2 Lbs. You randomly select a pumpkin from each store.

a. Find the mean difference in weights of the pumpkins.

b. Find the standard deviation of the difference in weights of the pumpkins.

c. If a Normal model can be used to describe the difference in weights between the pumpkins, what is the probability that the pumpkin from the second store is heavier than the pumpkin from the first?

d. What three assumptions must be made in order that a Normal model can be used to describe the difference in weights between the pumpkins?

i. That _________________________________________________________________________________

ii. That _________________________________________________________________________________

iii. That _________________________________________________________________________________

A sample of a salt that contains iron (II) ions, with a mass of 9.252 g, was dissolved in distiller water and made up to the mark in a 250.0 mL volumetric flask. 25.00 mL aliquot are pipetted from the stock solution, acidified, and titration with 0.02500 M potassium manganate(VII) solution. The manganate(VII) solution acts as an oxidizing agent in acid solution.

The volumes of manganate(VII) solution required to reach the end-point in three separate experiments were found to be, 20.95 mL, 20.75 mL and 20.90 mL respectively.

Use these data to calculate the % of iron in the salt.

mountain dew

It's voltage

A hockey player with a mass of 51.5 kg is traveling due east with a speed of 3.15 m/s. A second hockey player with a mass of 67.0 kg is moving due south with a speed of 6.65 m/s. They collide and hold on to each other after the collision, managing to move off at an angle θ south of east, with a speed of vf. Assume friction may be ignored and determine the following.

a) the angle θ __________ ° south of east

b) the speed vf ________m/s