What is the theoretical minimum force

AI Thread Summary
The discussion focuses on applying the Work-Energy Theorem to calculate the force acting on an 82.5 kg student who accelerates from rest to 97.5 m/s over a distance of 37.5 m. The provided equation appears correct, using the formula f = (0.5 * m * v^2) / s to find the force. Additionally, a question arises regarding the theoretical minimum force needed for a car jack, emphasizing the relationship between work input and output in an ideal machine. Another participant seeks clarification on the speed of a roller coaster using conservation of energy principles. The thread highlights the importance of understanding energy conservation and work in solving physics problems.
ownedbyphysics
Messages
15
Reaction score
0
a 82.500 kg student, starts from rest. A constant force acts on him for 37.5m to give him a speed of 97.5 m/s. Use the Work- energy theorem to find the magnitude of the force.

this is my equation which I'm unsure about
1. f*s= .5mv^2f - .5mv^2i
2. f= .5(82.5)(97.5^2)/37.5
I just want to know if I'm right so far, thanks!

What is the theoretical minimum force Matt must provide to the handle of his car jack if he moves his jack handle .45 m each time he lifts his 17000 N car .004m?

I have no idea how to do this one. F=mg?...

Hideaki Fukuda is in a 475.0kg roller coaster that is poised, motionless, atop a 77.50, hill. How fast will the frictionlest coaster be moving at the top of the next hill, 62.250 m high?
I don't understand this problem and I have no idea what equation to use.
help please!
 
Physics news on Phys.org
ownedbyphysics said:
a 82.500 kg student, starts from rest. A constant force acts on him for 37.5m to give him a speed of 97.5 m/s. Use the Work- energy theorem to find the magnitude of the force.

this is my equation which I'm unsure about
1. f*s= .5mv^2f - .5mv^2i
2. f= .5(82.5)(97.5^2)/37.5
I just want to know if I'm right so far, thanks!

What is the theoretical minimum force Matt must provide to the handle of his car jack if he moves his jack handle .45 m each time he lifts his 17000 N car .004m?

I have no idea how to do this one. F=mg?...

Hideaki Fukuda is in a 475.0kg roller coaster that is poised, motionless, atop a 77.50, hill. How fast will the frictionlest coaster be moving at the top of the next hill, 62.250 m high?
I don't understand this problem and I have no idea what equation to use.
help please!
Your first one looks good. For the jack problem, assuming the mahine is ideal and loses no energy, the work output is equal to the work input. For the last one, it is all about conservation of energy. In the absence of friction, the sum of kinetic energy plus gravitational potential energy is constant.
 
Thread 'Collision of a bullet on a rod-string system: query'

Thread 'Collision of a bullet on a rod-string system: query'

In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
View full post »
Thread 'A cylinder connected to a hanged mass'

Thread 'A cylinder connected to a hanged 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

What Is the Normal Force on a Rollercoaster Car at the Top of a Hill?
Replies
3
Views
3K
What Minimum Radius Prevents Cars from Leaving the Road on a Steep Hill?
Replies
1
Views
13K
How Fast Must a Car Go to Clear a 12m Loop and What Are the Max G-Forces?
Replies
7
Views
6K
What is the force of the track on the car?
Replies
1
Views
4K
What are some challenging dynamics practice problems for next week's assignment?
Replies
23
Views
11K

Hot Threads

Recent Insights

Back
Top