A block of mass m=2 kg is initially at rest | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) $1$. First, we determine the normal force $F_N$ acting on the block. The forces in the vertical direction are the upward force $F_2$, the normal f

Vedclass · Accepted Answer

$2.5$

Vedclass · Answer

(A) $1$. First, we determine the normal force $F_N$ acting on the block. The forces in the vertical direction are the upward force $F_2$, the normal force $F_N$, and the downward gravitational force $mg$. Since the block is not moving vertically, the net vertical force is zero:$F_2 + F_N - mg = 0$$10 \ N + F_N - (2 \ kg)(10 \ m/s^2) = 0$$10 \ N + F_N - 20 \ N = 0$$F_N = 10 \ N$$2$. Next, we calculate the limiting static friction force $f_{s,max}$:$f_{s,max} = \mu_s F_N = 0.4 	imes 10 \ N = 4.0 \ N$$3$. The applied horizontal force is $F_1 = 6 \ N$. Since the applied horizontal force $F_1$ is greater than the limiting static friction force $f_{s,max}$ $(6 \ N > 4.0 \ N)$, the block will start to move.$4$. Once the block is in motion, the frictional force acting on it is the kinetic friction force $f_k$:$f_k = \mu_k F_N = 0.25 	imes 10 \ N = 2.5 \ N$Therefore, the magnitude of the frictional force acting on the block is $2.5 \ N$.

Similar Questions

$A$ body of mass $1 \,kg$ is moving with a velocity $10 \,ms^{-1}$ on a horizontal rough surface having a coefficient of kinetic friction $0.4$. If the constant force is removed, the body comes to rest in a time (Acceleration due to gravity $g = 10 \,ms^{-2}$). (in $\,s$)

The power required for an engine to maintain a constant speed of $50 \,m \,s^{-1}$ for a train of mass $3 \times 10^6 \,kg$ on rough rails is (The coefficient of kinetic friction between the rails and wheels of the train is $0.05$ and acceleration due to gravity $= 10 \,m \,s^{-2}$).

$A$ block of mass $5 \ kg$ is placed on a rough horizontal surface having a coefficient of friction $0.5$. If a horizontal force of $60 \ N$ is acting on it,then the acceleration of the block is (Acceleration due to gravity,$g = 10 \ ms^{-2}$). (in $ms^{-2}$)

Vedclass Test Series

Exam Paper Generator

Online Exam Module