[serenitymantra]

Suppose you begin sliding down a 15 degree ski slope. Ignoring air resistance, how fast will you be moving after 10s?

I need help setting it up. Any guidance will be appreciated. Thanks!

[ebaines]

Remember that F=ma. Here F is the force of gravity along a 15 degree incline. If you resolve the force of gravity into components along the slope and perpendicular to the slope, you should be able to see that here F = mg sin(15 deg). So now you can determine its acceleration a. The next step is to apply the equation of motion for a body under constant acceleration to find its velocity at t=10 sec.

[serenitymantra]

Remember that F=ma. Here F is the force of gravity along a 15 degree incline. If you resolve the force of gravity into components along the slope and perpendicular to the slope, you should be able to see that here F = mg sin(15 deg). So now you can determine its acceleration a. The next step is to apply the equation of motion for a body under constant acceleration to find its velocity at t=10 sec.

Ma? Mg?

[ballengerb1]

Do you want an answer that also ignores friction as well as air resistance?

[ebaines]

ma? mg?

Oh boy. Given the data you've provided the only way to do this problem is to start with an understanding of Newtons' 3rd Law:

F = ma, or Force = mass time acceleration.

Does this sound familiar? If not, then you'd better go back and read your text book.

[serenitymantra]

Do you want an answer that also ignores friction as well as air resistance?

Yes, ignoring both friction and air resistance.

[serenitymantra]

Oh boy. Given the data you've provided the only way to do this problem is to start with an understanding of Newtons' 3rd Law:

F = ma, or Force = mass time acceleration.

Does this sound familiar? If not, then you'd better go back and read your text book.

We never talked about force. This is the guy's 1st time teaching, so he's going pretty fast and everyone in this class is lost.

[ballengerb1]

He is going fast likely out of fear. Ask/tell him to slow down and try to give more examples and visuals. I supervise first year science teachers who graduate from our university with a type 25 teaching certificate. Its very common for them to go too fast, ask for more examples.

[ebaines]

I suppose you can ignore force if you simply assume that the acceleration along the slope is a = g sin(15 degrees). Here g is the acceleration due to gravity, or 9.8 m/s^2. From this you can determine the velocity after 10 seconds.

[serenitymantra]

He is going fast likely out of fear. Ask/tell him to slow down and try to give more examples and visuals. I supervise first year science teachers who graduate from our university with a type 25 teaching certificate. Its very common for them to go too fast, ask for more examples.

We try. He just looks at us and say.. it's easy guys.. it's not that difficult. I told him I wanted some tutoring from the lab, his response is that 'don't try to hard.'

[serenitymantra]

I suppose you can ignore force if you simply assume that the acceleration along the slope is a = g sin(15 degrees). Here g is the acceleration due to gravity, or 9.8 m/s^2. From this you can determine the velocity after 10 seconds.

I did that initially, but I wasn't sure I was on the right track. I ended up with 25.4 m/s.

[ballengerb1]

Half of us graduated in the top half of our class, the rest did not.

[ebaines]

I did that initially, but I wasn't sure I was on the right track. I ended up with 25.4 m/s.

You got it - 25.4 m/s is correct.

[babybean_06]

Suppose you begin sliding down a 15 degree ski slope. Ignoring air resistance, how fast will you be moving after 10s?

I need help setting it up. Any guidance will be appreciated. Thanks!

7m

[brat269]

9.8m/s*sin(15) *10
25m/s

[gertkip]

a=+gsin theta
a=9.8(sin 15)
a=2.54m/s^2
however a= change in velocity/time
velocity=a*time
2.54*10= 25.4m/s