ATAR Notes: Forum

VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Specialist Mathematics => Topic started by: itolduso on October 03, 2010, 10:35:26 pm

Title: reaction
Post by: itolduso on October 03, 2010, 10:35:26 pm: A 5 kg object is pulled up an inclined plane at 30deg to the horizontal at constant speed. The pulling rope is parallel to the inclined plane and has a tension of 40 newtons. Find the reaction force of the inclined plane on the object.
Title: Re: reaction
Post by: Yitzi_K on October 03, 2010, 10:51:40 pm: As the pulling force acting on the object is parallel to the plane, the reaction force will be equal to the component of the weight force that is perpendicular to the plane, i.e. $5g \times \cos(30)$ which is $\frac{5g\sqrt{3}}{2}$
Title: Re: reaction
Post by: itolduso on October 03, 2010, 11:00:05 pm: the answer is 45.2
Title: Re: reaction
Post by: Yitzi_K on October 03, 2010, 11:45:29 pm: Hmmm something looks a little strange to me about this question. Given F=ma, if the object is moving at a constant speed, the net force must be equal to zero, yet it isn't. Unless I'm missing something here?
Title: Re: reaction
Post by: chansthename on October 05, 2010, 08:34:04 pm: yeah, as you have said it should just be the normal, maybe the answer is wrong.
Title: Re: reaction
Post by: itolduso on October 05, 2010, 09:41:03 pm: my teacher said 45.2 is right