A block of mass 10 kg is resting on a horizontal surface. If the coefficient of
Practice Questions
Q1
A block of mass 10 kg is resting on a horizontal surface. If the coefficient of kinetic friction is 0.3, what is the frictional force acting on the block when it is sliding?
30 N
20 N
10 N
15 N
Questions & Step-by-Step Solutions
A block of mass 10 kg is resting on a horizontal surface. If the coefficient of kinetic friction is 0.3, what is the frictional force acting on the block when it is sliding?
Correct Answer: 30 N
Step 1: Identify the mass of the block, which is given as 10 kg.
Step 2: Identify the coefficient of kinetic friction, which is given as 0.3.
Step 3: Calculate the weight of the block (N), which is the force due to gravity. Use the formula: N = mass (m) * gravity (g). Here, g is approximately 9.8 m/s².
Step 4: Substitute the values into the formula: N = 10 kg * 9.8 m/s² = 98 N.
Step 5: Use the formula for frictional force (f_k): f_k = μ_k * N, where μ_k is the coefficient of kinetic friction.
Step 6: Substitute the values into the formula: f_k = 0.3 * 98 N.
Step 7: Calculate the frictional force: f_k = 29.4 N.
Step 8: Round the answer to the nearest whole number if needed: approximately 30 N.
Frictional Force Calculation – Understanding how to calculate the frictional force using the coefficient of kinetic friction and the normal force.
Normal Force – Recognizing that the normal force (N) is equal to the weight of the block when on a horizontal surface.
Units and Constants – Applying the correct units and constants, such as gravitational acceleration (9.8 m/s²) in calculations.
