A block of mass 5, kg is on a rough horizontal surface and is at rest. Now a force of 24, N is impar

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4-2.Friction

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A block of mass $5\, kg$ is on a rough horizontal surface and is at rest. Now a force of $24\, N $is imparted to it with negligible impulse. If the coefficient of kinetic friction is $0.4$ and $g = 9.8\,m/{s^2}$, then the acceleration of the block is ........ $m/s^2$

A$0.26$

B$0.39$

C$0.69$

D$0.88$

Solution

(d) Net force = Applied force -Friction force
$ma = 24 – \mu \;mg$
$ = 24 – 0.4 \times 5 \times 9.8$ $ = 24 – 19.6$
$⇒$ $a = \frac{{4.4}}{5} = 0.88\;m/{s^2}$

Standard 11

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(AIPMT-1992)

A block of mass $5\, kg$ is on a rough horizontal surface and is at rest. Now a force of $24\, N $is imparted to it with negligible impulse. If the coefficient of kinetic friction is $0.4$ and $g = 9.8\,m/{s^2}$, then the acceleration of the block is ........ $m/s^2$

Solution

Similar Questions

A block is projected with speed $20 \,m / s$ on a rough horizontal surface. The coefficient of friction $(\mu)$ between the surfaces varies with time $(t)$ as shown in figure. The speed of body at the end of $4$ second will be ………… $m / s$ ( $g=$ $10 \,m / s ^2$ )

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$Assertion$ : On a rainy day it is difficult to drive a car or bus at high speed.
$Reason$ : The value of coefficient of friction is lowered due to wetting of the surface