Log in KJ 8 years agoPosted 8 years ago. Direct link to KJ's post “Why should vector c be +3...” Why should vector c be +3? instead of making the black line from (-4,-7) to (-1,-7) if I make the black line from (-1,0) to (-4,0) then I shall get -3 right? Then how can I say if vector c is + or minus 3? • (1 vote) Seán 8 years agoPosted 8 years ago. Direct link to Seán 's post “The x component is = to t...” The x component is = to the change in x. To get this you take the terminal (end) point and subtract the start point. In the case of vector c we have -1 - -4 = -1+4 = 3. (3 votes) zacharias.harris 8 years agoPosted 8 years ago. Direct link to zacharias.harris's post “In 1:49 how do you know a...” In • (4 votes) Kathryn Boyle 8 years agoPosted 8 years ago. Direct link to Kathryn Boyle's post “You can tell because it i...” You can tell because it is the point... not the arrow. In vectors, direction matters. The point represents the starting point. Tushar Mishra 8 years agoPosted 8 years ago. Direct link to Tushar Mishra's post “Dear sal sir you have stu...” Dear sal sir you have studied us about vectors in this section only graphs but what about their analytical method. • (6 votes) saxman13579 8 years agoPosted 8 years ago. Direct link to saxman13579's post “At the time 1:31, Sal sai...” At the time • (4 votes) zacharias.harris 8 years agoPosted 8 years ago. Direct link to zacharias.harris's post “In 1:49 how do you know a...” In • (1 vote) ashonfire 8 years agoPosted 8 years ago. Direct link to ashonfire's post “Look at the point with th...” Look at the point with the v-shape. That tells you the end point of the vector or the terminating point. Follow the components in reverse to find the initial point. That's how you know at which point to start. (4 votes) TriQuang 7 years agoPosted 7 years ago. Direct link to TriQuang's post “how can I solve a vector ...” how can I solve a vector as a word problem? • (1 vote) meppydc 6 years agoPosted 6 years ago. Direct link to meppydc's post “When I see this kind of p...” When I see this kind of problem, a good start is to draw the diagram with the forces at play, since this looks like a physics problem. There is the gravitational force (Fg), the normal force (Fn), and the applied force (Fa) to keep the cart in place. Friction can't be calculated from the given information so it's assumed to be a frictionless plane. Fg is 200 pounds and points downward from the cart, so the other two forces must cancel it out. Fn is always perpendicular to the surface while Fa is parallel to the incline. The 3 vectors then form a triangle with Fg as the hypotenuse because Fn and Fa must form the opposing force that cancels Fg. You should be able to find that the angle between Fg and Fn is 30 using right triangles. Then you can apply trig and find out that Fa is 100 pounds (200sin(30) = 100). Fn = 200cos(30)= 173.2050808... If my explanation didn't make sense (it is pretty bad) then go to khan academy's section on physics. I hoped this helped (4 votes) jelaniboy1 8 years agoPosted 8 years ago. Direct link to jelaniboy1's post “how do you know which dir...” how do you know which direction to go? • (1 vote) Sheikheddy 8 years agoPosted 8 years ago. Direct link to Sheikheddy's post “You look at the starting ...” You look at the starting and ending point to determine the direction of the vector. That means, you look for an arrow in the line, which shows you the 'head' and 'tail'. The front of the arrow is the end point, also known as the terminal point, while the back of the arrow is the start point, the initial point. Then, you look for the x and y changes needed to go from the initial TO the terminal point. For example, if you have an initial point of (0, 0) and a terminal point of (1, 1) then the arrow will point toward the point (1,1) and we know that the horizontal and vertical [x and y] 'movements' have a size of, a magnitude of one. (3 votes) Mc Nolasco 5 years agoPosted 5 years ago. Direct link to Mc Nolasco's post “Is it like getting the sl...” Is it like getting the slope of a linear function? • (0 votes) Favour Rege 5 years agoPosted 5 years ago. Direct link to Favour Rege's post “Well, yes but actually no...” Well, yes but actually no... It's more like determining the change in the x-axis, then the change in the y-axis and plugging in those values in this bracket: ( ▲x , ▲y ). (3 votes) Shimmy 7 years agoPosted 7 years ago. Direct link to Shimmy's post “Does it make any differen...” Does it make any difference where you start the vector as long as you maintain its magnitude and direction? • (1 vote) Norawee Kaweepati 6 years agoPosted 6 years ago. Direct link to Norawee Kaweepati's post “The start of the vector d...” The start of the vector doesn't really matter but sometimes it can be useful so don't change it just in case. (1 vote) Anwei Mi 6 years agoPosted 6 years ago. Direct link to Anwei Mi's post “How do vectors and scalar...” How do vectors and scalars differ from each other? • (1 vote) poddymosopoddy 6 years agoPosted 6 years ago. Direct link to poddymosopoddy's post “Vectors have a magnitude ...” Vectors have a magnitude and a direction. (1 vote)Want to join the conversation?
1:49
1:31 1:49
For example: a 200-pound cart sits on a ramp inclined at 30 degrees. What force is required to keep the cart from rolling down the ramp?
I know that the solution is 100 pounds, but I'm not sure how to approach that answer using trig.
https://www.khanacademy.org/science/physics/forces-newtons-laws#inclined-planes-friction
Scalars do not have directions, only magnitudes.
