What are the solutions to these work and energy problems?

AI Thread Summary
To solve work and energy problems, key formulas include gravitational potential energy (PE = mgh) and kinetic energy (KE = 0.5mv²). For the ball dropped from 6m, its velocity at 1m can be calculated using energy conservation principles. Similarly, the velocity of an object dropped from height h when at 0.5h can also be derived from these formulas. To find the average force exerted by the football player, use the work-energy principle, where work done equals force times distance. Understanding and applying these formulas will clarify the solutions to the problems presented.
losthelp
Messages
10
Reaction score
0
Work and energy problems :(

can anyone help me w. these, I am completely lost!

A 0.046-kg ball is dropped froma height of 6m above the ground. When it is 1m above the ground, its velocity will be:

An object is dropped from a small height h above the ground. When its height is 0.5h, its velocity will be:

A football player cfan expend 100J energy on the football when he throws it. If the average distance through which eh accelerates is 1.2m what is the average force that he exerts on the ball?

i know these are suppose to be simple but I am compeltey lost :( help please!
 
Physics news on Phys.org


First you need formulas, all this problems are straightforward, so just get the formulas and plug in values.
 

Thread 'Errors and significant figures'

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...
View full post »
Thread 'A cylinder connected to a hanging mass'

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...
View full post »

Similar threads

Work done during a collision -- Change in Kinetic Energy & change in Momentum
Replies
1
Views
2K
Avg Power in a Rotational Energy/Work Problem
Replies
6
Views
1K
Potential energy and work relationship
Replies
6
Views
1K
Question about the Kinetic Energy of a baseball in flight
Replies
8
Views
3K
Work Required to Move a Piano Onto a Truck
Replies
1
Views
1K
Conservation of Energy with Gravitational Potential Energy
Replies
6
Views
2K
Confused on potential energy losses and regain.
Replies
1
Views
1K
Conservation of energy problem: Ball rolling down inclined plane and then through a loop-the-loop
Replies
10
Views
2K
Energy/Work Problem: Friction of sliding down pole
Replies
5
Views
4K
Problem involving energy/motion
Replies
19
Views
2K

Hot Threads

Recent Insights

Back
Top