Question

What is the magnitude of the force needed to keep a 60 newton rubber block moving across level,dry asphalt in a straight line at a constant speed of 2.0 meters per second

Answer 1

let Coefficients of Friction of Rubber on asphalt (dry) =0.7

F= Coefficients of Friction * normal force = 0.7 * 60 =42 N

so the net force of the rubber is zero, meaning it will travel at a constant speed.

When the rubber is travel at 2m/s, 42N is required to keep moving at constant speed

Answer 2

Answer:

F = 40.2 N

Explanation:

Weight of the rubber block, W = 60 N

If m is the mass of the rubber block,

$m=\dfrac{W}{g}$

$m=\dfrac{60\ N}{9.8\ m/s^2}$

m = 6.12 kg

We know that the coefficient of friction between rubber block and dry asphalt is, $\mu_k=0.67$

The relation between the coefficient of friction and the force is given by :

$F=\mu_k N$

Here, N = W

$F=\mu_k W$

$F=0.67\times 60\ N$

F = 40.2 N

So, the magnitude of force needed to keep a 60 newton rubber block moving across level,dry asphalt in a straight line is 40.2 N. Hence, this is the required solution.