Finding an expression for acceleration

In summary, a 5.21 kg block is sliding down a slope at an angle of 4.22° to the horizontal with an initial speed of 1.45 m s−1. The coefficients of friction between the block and slope are μs = 0.500 and μk = 0.100. After attempting to find an expression for the acceleration of the block down the slope, a, the equation a=g*sin(θ)-μk*cos(θ) was determined but was later found to be incorrect due to one term being an acceleration and the other being dimensionless.
  • #1
Mitza
5
0

Homework Statement



A 5.21 kg block is sliding down a slope at an angle of 4.22° to the horizontal.

The block is initially moving down the slope at a speed of 1.45 m s−1 and the coefficients of friction between the block and slope are, μs = 0.500, and μk = 0.100.

Find an expression for the acceleration of the block down the slope, a. (Your expression should give a positive value when the block is accelerating down the slope)

2. The attempt at a solution

I came up with the equation;

a=g*sin(θ)-μk*cos(θ)

However, I've been told this is incorrect so I don't really know what else to do?

Thanks in advance for any help!
 
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  • #2
Mitza said:
a=g*sin(θ)-μk*cos(θ)

However, I've been told this is incorrect
It is clearly wrong because of the two terms on the right one is an acceleration but the other is dimensionless. Did you omit something in writing it out?
If still stuck, please post your working.
 

Related to Finding an expression for acceleration

What is acceleration?

Acceleration is the rate at which an object's velocity changes over time. It is a vector quantity, meaning it has both magnitude and direction. It is typically measured in meters per second squared (m/s^2).

Why is it important to find an expression for acceleration?

Finding an expression for acceleration allows us to quantitatively describe how an object's velocity changes over time. This is important in understanding the motion of objects and predicting their future behavior.

How do you find an expression for acceleration?

An expression for acceleration can be found by dividing the change in velocity by the change in time. This is represented by the equation a = (vf - vi)/t, where a is acceleration, vf is final velocity, vi is initial velocity, and t is time.

What factors can affect acceleration?

Acceleration can be affected by various factors, such as the force applied to an object, its mass, and the direction of the force. Other factors that can affect acceleration include friction, air resistance, and the surface the object is moving on.

How is acceleration related to other kinematic quantities?

Acceleration is related to other kinematic quantities such as displacement, velocity, and time through a set of equations known as the kinematic equations. These equations can be used to solve for any of these quantities given the others, making it easier to analyze and understand the motion of objects.

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