A snowmobile does 400J of work in towing a sled to the top of a hill. During th etrip up the hill, it took 50J to overcome the work of friction. What is the potential energy of the motionless sled at the top of the hill?
Well I know that the formula for potential energy is mass * 9.8 m/s sq. * height.
But I can't figure this out.
Help?!
work done - friction= PE change
thanks.
A 500 kg car has an engine that uses only 40% of the energy from the gasoline for motion. If there is 15,000J of potential energy stored in the gasoline, how fast an the car go on the gasoline?
I have no idea how to set this up. Any help?!
To find the potential energy of the motionless sled at the top of the hill, you need to know the height of the hill and the mass of the sled. However, in the given information, only the work done by the snowmobile and the work done against friction are mentioned, not the actual values of height or mass.
Let's break down the problem and figure it out step by step:
1. Start by calculating the net work done on the sled. Net work is the total work done on an object, taking into account both the work done by external forces and the work done against friction. In this case, the net work is the work done by the snowmobile minus the work done against friction.
Net work = Work done by snowmobile - Work done against friction
Net work = 400 J - 50 J
Net work = 350 J
2. The net work done on the sled is equal to the change in its potential energy. So, you can use the formula for potential energy to find the height of the hill.
Net work = Potential energy
Net work = mgh
Where:
m is the mass of the sled
g is the acceleration due to gravity (approximately 9.8 m/s^2)
h is the height of the hill
3. Rearrange the formula to solve for height (h):
h = Net work / (mg)
Since the mass of the sled (m) is not given, we'll assume it cancels out in this equation. So, you don't need to know the mass of the sled to find the height.
h = Net work / (mg)
h = 350 J / (9.8 m/s^2)
h ≈ 35.7 meters
Therefore, the potential energy of the motionless sled at the top of the hill is given by the formula:
Potential energy = mass * 9.8 m/s^2 * height
Potential energy ≈ mass * 9.8 m/s^2 * 35.7 meters
Note that without knowing the mass of the sled, we cannot calculate the exact value of the potential energy. However, we can conclude that the potential energy increases with the height of the hill.