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1.) A 27 k g suitcase is being pulled with constant speed by a handle that is at

ID: 2136191 • Letter: 1

Question

1.) A 27 kg

suitcase is being pulled with constant speed by a handle that is at an angle of 28? above the horizontal.

(a) If the normal force exerted on the suitcase is 170

N , what is the force F applied to the handle?



2.) Your groceries are in a bag with paper handles. The handles will tear off if a force greater than 47.0

N is applied to them.

(a) What is the greatest mass of groceries that can be lifted safely with this bag, given that the bag is raised with constant speed.

(b) What is the greatest mass of groceries that can be lifted safely with this bag, given that the bag is raised with an acceleration of 1.60

m/s2 ?



3.) At the local grocery store, you push a 15.0-

kg shopping cart. You stop for a moment to add a bag of dog food to your cart. With a force of 13.0N , you now accelerate the cart from rest through a distance of 2.30m in 2.55s .

(a) What was the mass of the dog food?

Explanation / Answer

1) sum forces in teh y

F sin(28) + N - mg = 0

F = (27*9.81-170)/sin(28 degrees)=202.1 N


2)

a) T - mg = 0

m = T/g = 47/9.81=4.79 kg

b) T - mg = ma

m = T/(a + g) = 47/(9.81+1.6)=4.12 N


3) a) a = 13/(m+15)


x = 1/2 a t^2

2.3 = 0.5*(13/(m+15))*2.55^2

m=3.38 kg