# What amount of force must be applied to 6kg block moving at 13m/s to slow down to 5m/s in a distance of 4.5m?The Friction between them is 75N?

jeew-m | College Teacher | (Level 1) Educator Emeritus

Posted on

We can do this using Newtons second law of motion.

To stop the moving block we have to apply a force against its motion. Both friction and the applied force result in decrease the velocity of the block.

Using equations of motion

`V^2 = U^2+2aS`

`a = (V^2-U^2)/(2S)`

`a = (5^2-13^2)/(2xx4.5)`

`a = -16m/s^2`

Acceleration is negative because we have a deceleration.

Let us say the force is P at the opposite direction to the movement.

Using F = ma to the direction of motion

`-P-75 = 6xx(-16)`

`P = 21N`

So the required external force is 21N at the direction opposite to the movement of block.

Sources:
The text passage contains a physics problem that requires the calculation of the force needed to slow down a moving block, and the solution to this problem is provided in the text.
single_question_with_answer
Given a text passage, determine:
    1. If it contains a mathematical question (including word problems or calculations)
    2. If an answer to that mathematical question is provided in the text

First, describe the content structure you found in 1-2 sentences.

Then provide your analysis in the following format:
TYPE: <one of the following values>
- NO_QUESTION
- SINGLE_QUESTION
- SINGLE_QUESTION_WITH_ANSWER
- MULTIPLE_QUESTIONS
- MULTIPLE_QUESTIONS_WITH_ANSWERS
system
# What amount of force must be applied to 6kg block moving at 13m/s to slow down to 5m/s in a distance of 4.5m?The Friction between them is 75N?

jeew-m | College Teacher | (Level 1) Educator Emeritus

Posted on

We can do this using Newtons second law of motion.

To stop the moving block we have to apply a force against its motion. Both friction and the applied force result in decrease the velocity of the block.

Using equations of motion

`V^2 = U^2+2aS`

`a = (V^2-U^2)/(2S)`

`a = (5^2-13^2)/(2xx4.5)`

`a = -16m/s^2`

Acceleration is negative because we have a deceleration.

Let us say the force is P at the opposite direction to the movement.

Using F = ma to the direction of motion

`-P-75 = 6xx(-16)`

`P = 21N`

So the required external force is 21N at the direction opposite to the movement of block.

Sources:
user
The text passage contains a physics problem that requires the calculation of the force needed to slow down a moving block, and the solution to this problem is provided in the text.

TYPE: SINGLE_QUESTION_WITH_ANSWER