How to Calculate Speed at Different Points Using Conservation of Energy?

AI Thread Summary
To calculate the speed of a block at different points using conservation of energy, one must consider both kinetic and potential energy. The initial speed of the block at Point A is 7 m/s, and its mass is 8 kg. The problem requires determining the speed at Points B and C while neglecting friction. The approach involves using gravitational potential energy to assess changes in speed as the block moves. The relevant equations for kinetic and potential energy will guide the calculations.
Peterson
Messages
42
Reaction score
0
INTRODUCTION:
This is a problem from my Introduction to Physical Science class using "Conceptual Physics" 10th Ed.by Paul G. Hewitt

EXACT PROBLEM:
"The block in the figure at the right has a mass of 8kg and an initial speed of 7 m/s at Point A. Neglect frictional forces."

PROBLEMS FACED:
a) What will be its speed when it reaches Point B?
b) What will be its speed when it reaches Point C?

MY THOUGHTS:
Should I be looking for kinetic energy? What am I doing here?
 
Physics news on Phys.org
This is the diagram:

physics-1.jpg
 
Kinetic and Potential energy. Looks like an application of work energy/
 
I would think that speed is in this case equal to the initial plus any provided by external forces. In this case, the only other force is gravity. So as you suggest use th potential energy from gravity to add to the initial velocity. Whats that eqn?
 
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
View full post »

Similar threads

Conservation of Momentum Problem - Mechanical and Kinetic Energies
Replies
2
Views
954
Conservation of Mechanical Energy - Which Equation To Use?
Replies
9
Views
1K
Conservation of Energy with Gravitational Potential Energy
Replies
6
Views
2K
Car-Car System: Energy Conservation?
Replies
2
Views
1K
Solving Orbital Speed with Energy & Angular Momentum Conservation
Replies
7
Views
2K
Is potential energy defined only for internal conservative forces?
Replies
15
Views
1K
Spring Problem Involving Variables and Constants Only
Replies
3
Views
1K
Question about the conservation of mechanical energy
Replies
7
Views
2K
Problem with when to use Force and Energy. What compresses spring/
Replies
3
Views
1K
What is considered the "System" here? (conservation of energy problem)
Replies
20
Views
3K

Hot Threads

Recent Insights

Back
Top