maximum friction force = mu m g
= .2 * .4 * 9.81 = .787 Newtons
so it is less than or equal to .787 Newtons (or .78 N if you use 9.8 for g and round to two significant figures)
It is no larger than 0.78 N.
It is 0.08 N.
It is 0.78 N.
It is no smaller than 0.78 N.
= .2 * .4 * 9.81 = .787 Newtons
so it is less than or equal to .787 Newtons (or .78 N if you use 9.8 for g and round to two significant figures)
The force of static friction can be calculated using the equation:
f_s = μ_s * N
where f_s is the force of static friction, μ_s is the coefficient of static friction, and N is the normal force.
In this case, the coefficient of static friction is given as 0.20. The normal force is equal to the weight of the block, which can be calculated using:
N = m * g
where m is the mass of the block and g is the acceleration due to gravity.
Given that the mass of the block is 0.40 kg, and the acceleration due to gravity is approximately 9.8 m/s^2, we can calculate the normal force:
N = 0.40 kg * 9.8 m/s^2 = 3.92 N
Using this value for the normal force and the coefficient of static friction, we can calculate the maximum force of static friction:
f_s = 0.20 * 3.92 N = 0.784 N
Therefore, the force of static friction is no larger than 0.78 N.
fs = μs * N
where fs is the force of static friction, μs is the coefficient of static friction, and N is the normal force.
The normal force N is equal to the weight of the block, which can be calculated by multiplying the mass of the block (0.40 kg) by the acceleration due to gravity (9.8 m/s^2):
N = m * g
N = 0.40 kg * 9.8 m/s^2
N = 3.92 N
Substituting the values into the equation for static friction:
fs = 0.20 * 3.92 N
fs = 0.784 N
Therefore, the force of static friction acting on the block is 0.784 N.
The statement "It is no larger than 0.78 N" is incorrect because the force of static friction is exactly 0.784 N, which is larger than 0.78 N.
The statement "It is 0.08 N" is incorrect because 0.08 N is not equal to the force of static friction.
The statement "It is no smaller than 0.78 N" is incorrect because the force of static friction is not larger than 0.784 N.
The correct statement is "It is 0.78 N," as the force of static friction is exactly that value.