110 Answered Questions for the topic Energy
A boy pulls a rope attached to a 22 kg sled on an icy, frictionless surface with an acceleration of 2.0 m/s2. Calculate the work done by the boy if he is pulling the rope at 35° to the horizontal... more
A roller coaster goes over a 15 m tall hill then approaches a 29 m hill. What is the minimum velocity the roller-coaster would need when going over the 15 m hill to make it to the top of the 29 m... more
A rectangular room of length 6 metres has six 18 W LED lights.
What is the maximum width of the room if the lamp power density requirement of 5W/m^2 (5 Watts per metre squared) is to be met?
Conservation of Energy
The potential energy function of a conservative force acting on an object is given by the expressionU=y-2x2-2xwhere U is in joules and x, y, z are in meters. Consider the following two points in... more
I know the standard formula, but how would I use it in this context?
The Sun generates energy at the rate of about 3.9 × 1026 W. Use Einstein’s equation to verify that the Sun loses mass at the rate of about 4 million tonnes per second.
Physics Energy Question
A ray of light strikes a side of lucite ( = 1.50) prism at 40° as shown below. Find the angle that the light leaves the prism.The prism is a isosceles with a degree of 70 at the top.
Physics Energy Question
A 5.0 kg crate is pushed across a horizontal surface by a 60.0 N force directed 32°C below the horizontal. Determine the work done on the crate by this force after the crate moves 8.0 m.
Physics Energy Question
A 12 Kg object starts at rest on a horizontal surface. The object is pushed along the surface with a net force of 8.0 N. What is the speed of the object after it has traveled 5.0 m?a) Solve using... more
Pop-up Toy Physics Situation
Please help. An inventor has created a spring-loaded toy that pops up off the table when compressed and released. The toy consists of two connected parts by a stiff spring as shown, with one of the... more
You are pushing a large box across a frictionless.....(IN THE DESCRIPTION)
You are pushing a large box across a frictionless floor by applying a constant horizontal force. If the box starts at rest, you have to do work W_1 in order for the box to travel a distance d in... more
Your physics book is resting in front of you on a horizontal table in the campus library. You push the book over to your friend,...... (IN THE DESCRIPTION)
Your physics book is resting in front of you on a horizontal table in the campus library. You push the book over to your friend, who is seated at the other side of the table, 0.400 m m north and... more
Which of the following are identical amounts of energy?
1kJ and 1 kcal1kJ and 239 cal1kJ and 1 Cal4.184 J and 1 kcal
how does pressure relate to elastic potential energy?
What is the equation for energy?
I guess I’m looking for the mathematical equation
Average Kinetic Energy of 2 Objects
If I had 2 objects of equal mass ( 10kg for example ), and knew that the average speed of the 2 objects was 8 ms-1 , is it possible to calculate the average kinetic energy of the 2 objects. I... more
A jet of mass 4,277 kg lands on an airstrip, stopping after a distance of 727 m and has an initial landing speed of 29 m/s.
What is the work done, in Joules, by non-conservative forces to stop the jet?
How high can a hike climb with the energy from a candy bar?
A candy bar label says it has 240 Calories (240,000 calories). Typical efficiency of energy conversion for a human is 25%. If a 68kg person were to use the energy in the candy bar to climb a... more
Physics- Work/ Energy
Michael uses his bike to apply 407 N to himself and the bike by pedaling as he approaches a 1.5 m tall ramp which is 7.4 m away. He starts from rest to accomplish this feat. How fast will he be... more
A projectile of mass 5.0 kg is shot
A projectile of mass 5.0 kg is shot horizontally with an initial speed of 17 m/s from a height of 25.0 m above a flat desert surface. For the instant before the projectile hits the surface,... more
What is the answer?
1. a worker pushes in 50.0 kg box on a level floor at constamt velocity and moves a distance of 10.0 m. If a person pushes it with a force of 850N, what must be the magnitude and the direction of... more
What does “energy transfer in cells” mean?
ADP and ATP are involved in energy transfer in cells. I know what is ATP and I know how ADP is formed, but I don’t understand what “energy transfer in cells” means.
Why alpha particles inestead of hydrogen or duetereum?
I know atoms undergoing alpha decay emit alpha particles, but I was wondering why specifically helium nuclei? If these atoms wanted to emit the smallest unit of matter (I'm talking about hadrons... more
Does endo- and (or) exocytosis require energy? Do they belong to active / passive transport?
I expect vesicle formation and fusion to require energy input; however, I'm not sure about which of endocytosis and exocytosis require energy and how they use the energy input.Do they belong to... more
How do I describe and calculate the effect of an impacting object?
My lab studies the physiology of impact injury on biological tissues. I use a pneumatic cylinder to impart injury into a biological sample and then assess the molecular and physiological changes in... more