A rock rolling down an incline-velocity and force

AI Thread Summary
To calculate the velocity of a 20-ton spherical rock rolling down a 400-meter incline, the conservation of energy principle is applied. Initially, the rock possesses gravitational potential energy, which converts to kinetic energy as it reaches ground level. The velocity can be determined using the formula derived from energy conservation, where potential energy equals kinetic energy. Additionally, the force exerted on the rock can be calculated using Newton's second law, factoring in its mass and acceleration. Understanding these concepts is crucial for solving the problem accurately.
NDbogan
Messages
18
Reaction score
0
The question is:
a spherical rock weighing 20 tons starts rolling down a steep incline from a height of 400 metres. Calculate the velocity when it reaches the ground level. What is the force exerted on the rock?


I've tried to work this out but I just can't seem to grasp exactly what I'm missing.

Any help will be really appreciated.
 
Physics news on Phys.org
Conservation of energy ::biggrin::
 
hmm...could you explain it a bit further.
 
Use conservation of energy. The energy the rock has at the start and what is the energy converted to when it reaches the bottom
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top