A box of mass 4 kg is held at rest on a plane inclined at an angle

[Mxcve]

Hello, can anyone help me explain what to do with this question


A box of mass 4 kg is held at rest on a plane inclined at an angle [math]25^o[/math] to the horizontal. The box is than released and slides down the plane.

a) A simple model assumes that the only forces acting on the box are its weight and the normal reaction from the plane. Show that, according to this simple model, the
acceleration of the box down the plane is 0.436 ms-2, correct to three significant figures.

b) In fact, the box moves down the plane with constant acceleration and takes 2 s to travel 0.8m. By using this information, find the acceleration of the box.

c) Explain why the answer to part b is less than the answer to part a.

 

[stapel]

Hello, can anyone help me explain what to do with this question

We'll be glad to help! But first we need to be able to see where you're getting stuck. So please reply with a clear listing of your thoughts and efforts so far. (Read Before Posting)

A box of mass 4 kg is held at rest on a plane inclined at an angle [imath]25\degree[/imath] to the horizontal. The box is then released and it slides down the plane.

a) A simple model assumes that the only forces acting on the box are its weight and the normal reaction from the plane. Show that, according to this simple model, the acceleration of the box down the plane is 0.436 ms-2, correct to three significant figures.

b) In fact, the box moves down the plane with constant acceleration and takes 2 s to travel 0.8m. By using this information, find the acceleration of the box.

c) Explain why the answer to part b is less than the answer to part a.

 

[blamocur]

Show that, according to this simple model, the
acceleration of the box down the plane is 0.436 ms-2, correct to three significant figures.

That number would be correct for [imath]2.548 \degree[/imath] angle

 

[Qwertyuiop[]]

Hello, can anyone help me explain what to do with this question


A box of mass 4 kg is held at rest on a plane inclined at an angle [math]25^o[/math] to the horizontal. The box is than released and slides down the plane.

a) A simple model assumes that the only forces acting on the box are its weight and the normal reaction from the plane. Show that, according to this simple model, the
acceleration of the box down the plane is 0.436 ms-2, correct to three significant figures.

b) In fact, the box moves down the plane with constant acceleration and takes 2 s to travel 0.8m. By using this information, find the acceleration of the box.

c) Explain why the answer to part b is less than the answer to part a.

isn't this physics?

 

[Qwertyuiop[]]

Hello, can anyone help me explain what to do with this question


A box of mass 4 kg is held at rest on a plane inclined at an angle [math]25^o[/math] to the horizontal. The box is than released and slides down the plane.

a) A simple model assumes that the only forces acting on the box are its weight and the normal reaction from the plane. Show that, according to this simple model, the
acceleration of the box down the plane is 0.436 ms-2, correct to three significant figures.

b) In fact, the box moves down the plane with constant acceleration and takes 2 s to travel 0.8m. By using this information, find the acceleration of the box.

c) Explain why the answer to part b is less than the answer to part a.

Have you tried drawing a FBD? That will help you a lot in solving these kinds of problems.

 

[topsquark]

Hello, can anyone help me explain what to do with this question


A box of mass 4 kg is held at rest on a plane inclined at an angle [math]25^o[/math] to the horizontal. The box is than released and slides down the plane.

a) A simple model assumes that the only forces acting on the box are its weight and the normal reaction from the plane. Show that, according to this simple model, the
acceleration of the box down the plane is 0.436 ms-2, correct to three significant figures.

b) In fact, the box moves down the plane with constant acceleration and takes 2 s to travel 0.8m. By using this information, find the acceleration of the box.

c) Explain why the answer to part b is less than the answer to part a.

Part b) is motion under constant acceleration. Set an origin at the top of the plane, and call +x to be down the plane. You have four equations to choose from:
[imath]x = x_0 + v_0 t + \dfrac{1}{2} a t^2[/imath]

[imath]v = v_0 + a t[/imath]

[imath]x = \dfrac{(v_0 + v)t}{2}[/imath]

[imath]v^2 = v_0^2 + 2 a (x - x_0)[/imath]

-Dan