If a $2$ $2$ $k g$ $kg$ object moving at $10$ $10$ $m s^{- 1}$ $ms^-1$ slows to a halt after moving $25$ $25$ $m$ $m$ , what is the coefficient of kinetic friction of the surface that the object was moving over?

Question

If a $2$ $2$ $k g$ $kg$ object moving at $10$ $10$ $m s^{- 1}$ $ms^-1$ slows to a halt after moving $25$ $25$ $m$ $m$ , what is the coefficient of kinetic friction of the surface that the object was moving over?

1 Answer

Impact of this question

1490 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-06-17T13:19:58

$μ = \frac{F_{frict}}{m g} = \frac{4}{2 \times 9.8} = 0.20$ $\mu=F_"frict"/(mg)=4/(2xx9.8)=0.20$

Explanation:

The object's final velocity will be $v = 0$ $v=0$ $m s^{- 1}$ $ms^-1$ , the initial velocity $u = 10$ $u=10$ $m s^{- 1}$ $ms^-1$ and the distance $25$ $25$ $m$ $m$ . We can use this to find the object's acceleration (deceleration):

$v^{2} = u^{2} + 2 a s$ $v^2=u^2+2as$

$a = \frac{v^{2} - u^{2}}{2 s} = \frac{0^{1} - 10^{2}}{2 \times 25} = \frac{- 100}{50} = - 2$ $a=(v^2-u^2)/(2s)=(0^1-10^2)/(2xx25)=(-100)/50=-2$ $m s^{- 2}$ $ms^-2$

The frictional force will be given by $F_{frict} = m a = 2 \times - 2 = - 4$ $F_"frict"=ma=2xx-2=-4$ $N$ $N$

That is, the force is $4$ $4$ $N$ $N$ in the direction opposite to the initial motion.

The relationship between the frictional force and the object's weight force is $F_{frict} = μ F_{w} = μ m g$ $F_"frict"=\muF_w=\mumg$ .

Rearranging:

$μ = \frac{F_{frict}}{m g} = \frac{4}{2 \times 9.8} = 0.20$ $\mu=F_"frict"/(mg)=4/(2xx9.8)=0.20$

(frictional coefficients have no units)

Science

Math

Humanities

... and beyond

If a $2$ $2$ $k g$ $kg$ object moving at $10$ $10$ $m s^{- 1}$ $ms^-1$ slows to a halt after moving $25$ $25$ $m$ $m$ , what is the coefficient of kinetic friction of the surface that the object was moving over?

1 Answer

Explanation:

Related questions

Impact of this question

Science

Math

Humanities

... and beyond

If a 22 kgkg object moving at 1010 ms−1ms^-1 slows to a halt after moving 2525 mm, what is the coefficient of kinetic friction of the surface that the object was moving over?

1 Answer

Explanation:

Related questions

Impact of this question

If a $2$ $2$ $k g$ $kg$ object moving at $10$ $10$ $m s^{- 1}$ $ms^-1$ slows to a halt after moving $25$ $25$ $m$ $m$ , what is the coefficient of kinetic friction of the surface that the object was moving over?