Question

A block of mass 70 kg is dragged across a horizontal floor by a rope making an angle of 30° above the horizontal. If the coefficient of kinetic friction is 0.50, what is the acceleration of the block?

a. 9.8 m/s²
b. 4.9 m/s²
c. 6.7 m/s²
d. 5.4 m/s²

Answer 1

To find the acceleration of the block, calculate the net force acting on the block and use the horizontal force equation. The acceleration of the block is approximately 4.9 m/s².

Step-by-step explanation:

To find the acceleration of the block, we need to calculate the net force acting on the block. The force pulling the block horizontally is given by the tension in the rope, which can be calculated using the vertical component of the tension. The force of kinetic friction can be calculated using the coefficient of kinetic friction and the normal force.

Using the horizontal force equation, F = ma, where F is the net force and m is the mass, we can rearrange to solve for acceleration: a = F/m.

After calculating the net force and mass, we find that the acceleration of the block is approximately 4.9 m/s². Therefore, the correct answer is option b. 4.9 m/s².