If the co-efficient of static friction for a 5 kg rubber block is 0.3 how much more force is required to lift the block than to start it sliding?
I worked out force to get it sliding is 14.7 N (5*9.8*.3) but not sure about the upward force to lift it.
Lift it against gravity? Its weight, m*g
Thanks. This is what I thought but again the answer in my book was incorrect. So frustrating.
To determine the force required to lift the block, you need to consider the gravitational force acting on the block, which is equal to its weight. The weight of an object can be calculated using the formula:
Weight = mass × gravitational acceleration
In this case, the mass of the rubber block is given as 5 kg, and the gravitational acceleration on Earth is approximately 9.8 m/s². Therefore, the weight of the block is:
Weight = 5 kg × 9.8 m/s² = 49 N
So, to lift the block, you would need a force equal to its weight, which is 49 N.
To find out how much more force is required to lift the block than to start it sliding, you need to compare the force necessary to lift it (49 N) with the force used to start it sliding (14.7 N).
The difference between these two forces can be calculated by subtracting the force required to start sliding from the force required to lift:
49 N - 14.7 N = 34.3 N
Therefore, 34.3 Newtons more force would be required to lift the block compared to starting it sliding.