Answer:
7,166 hrs =430 minutes
Explanation:
Since both train are on the same track, going one towards the other, the relative speed is the addition of both, then the time they need to meet, and consistently crash, is the time that (65mph + 55 mph)=120mph need to travel the total distance of 860 miles, of course in this case one part is traveled by the first train and the rest by the other. Then to find the time we use a three rule
1 h --->120mi
X ---->860mi, then X=(860 mi* 1h)/120 mi = 43/6 hrs= 7,16666 hrs, turning this into minutes need that we notice 1h=60min, then 43/6 hrs *60 min/hrs = 430 minutes.
Answer:
310.5 J
Explanation:
The total work done by Martha is equal to the increase in gravitational potential energy of the package, which is equal to

where
(mg) = 45 N is the weight of the package
is the increase in height of the package
The package is carried up 3 flights of stairs, each one with a height of 2.3 m, so the total increase in heigth is

And so, the work done by Martha is

A watering can is used to hold a water that we will use to water the plants. The water has both mass and volume. Two watering cans are most often different by the volume they contain.
Many various units for volume are used but most often used unit is liter. In a metric system basic units are those such as meter, kilogram and liter while in imperial system units used are those such as foote, inch, pound and gallon.
Unit for volume in metric system is cubic meter. It is equal to a volume of a cube whose all sides measure 1m. This is equal to 1000L. For watering cans that contain several liters units used is decimeter cubed. 1dm^3 = 1L
We can calculate the acceleration of Cole due to friction using Newton's second law of motion:

where

is the frictional force (with a negative sign, since the force acts against the direction of motion) and m=100 kg is the mass of Cole and the sled. By rearranging the equation, we find

Now we can use the following formula to calculate the distance covered by Cole and the sled before stopping:

where

is the final speed of the sled

is the initial speed

is the distance covered
By rearranging the equation, we find d:
The electromagnetic spectrum is the system of frequencies that show electromagnetic radiation, respective wavelengths, and photon energies. Some examples of frequencies found on the electromagnetic spectrum are radio waves, microwaves, infrared, optical, ultraviolet, X-rays, and gamma-rays.