Siimple kinematics Homework help

[heytke]

question 1

do not know how to begin with this one

a shopper pushes a 8.7kg shopping cart up a 13 degrees incline, Find the horzontal force, F, needed to give the cart and acceleration of 1.37m/s2.

question 2

A 1.35g samara falls toward the ground with a constant speed of 1.3m/s. What is the force of air resistance exerted on the samara?

question 3

A 23 kg suitcase is being pulled by a handle that is at an angle of 25 degrees abouve the horizontal. If the normal force is exerted on the suitcase is 150N, what is the force F applied to the handle?

If you could point me in the right direction i would be very thankful.

Kelly

 

[SN1987a]

For your first question, I wonder in which direction the cart has to accelerate at 1.37m/s2. I will suppose it is in the direction in which it is moving, i.e. at 13 degrees from the horizontal.

In any case, you should approach the problem by figuring out what are the forces involved and what are their components in the direction in which you are interested.

In your case, you have two forces: gravitational force on the cart (pointing vertically downwards) and the horizontal force that's being applied onto the cart. However, you know that the total force in the direction of motion should produce an acceleration of 1.37m/s2 on the cart, so you can solve for the horizontal force.

Does this get you on the right track?

 

[heytke]

Thanks

That really helped, thanks a bunch