Concrete Block Incline acceleration question

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SUMMARY

The discussion centers on calculating the acceleration of a 25kg concrete block sliding down a 30-degree incline, using gravitational acceleration (g = 9.81 m/s²). The weight of the block is determined to be 245.25N, and the component of weight acting down the slope is calculated as 122.625N. The resulting acceleration is confirmed to be 4.905 m/s². Participants emphasize the importance of drawing a free body diagram to visualize the forces acting on the block.

PREREQUISITES
  • Understanding of basic physics concepts, specifically Newton's laws of motion.
  • Knowledge of trigonometric functions, particularly sine, for resolving forces.
  • Familiarity with free body diagrams for visualizing forces acting on objects.
  • Basic algebra skills for manipulating equations and solving for unknowns.
NEXT STEPS
  • Study the principles of inclined plane physics and how to derive acceleration.
  • Learn how to construct and interpret free body diagrams in physics problems.
  • Explore the effects of friction on inclined planes and how it alters acceleration.
  • Investigate the kinematic equations to calculate distance traveled over time under constant acceleration.
USEFUL FOR

Students studying physics, educators teaching mechanics, and anyone interested in understanding motion on inclined planes.

nwmyname
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Homework Statement


A concrete block of mass 25kg is placed on a smooth slope that makes an angle of 30 degrees with the horizontal. Ignoring the effects of air resistance, calculate
a) the acceleration of the block as it slides down (g = 9.81 ms-2)
b) the distance the block moves in 3 seconds

Homework Equations

The Attempt at a Solution


w = mg
w = 25 * 9.81 = 245.25N
Wsin(theta) = 245.25 * sin(30) = 122.625N
122.625N / 25kg = 4.905ms-2?
 
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so, what is the problem you are facing?
 
nwmyname said:
Is it correct?
Looks correct to me.
 
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Likes drvrm
nwmyname said:
Is it correct? @Verma S.P.

whether it is correct or not will decide your 'free body diagram! pl. draw a free body diagram for the forces operating/acting on the block !
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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