Explanation:
Speed of the marathon runner, v = 9.51 mi/hr
Distance covered by the runner, d = 26.220 mile
Let t is the time taken by the marathon runner. We know that the speed of the runner is given by total distance divided by total time taken. Mathematically, it is given by :



t = 2.75 hours
Since, 1 hour = 60 minutes
t = 165 minutes
Since, 1 minute = 60 seconds
t = 9900 seconds
Hence, this is the required solution.
The Electromagnetic spectrum.
Answer: Remain unchanged
Explanation:
The boat with water barrel overboard floats in swimming pool when weight of the water displaced by the boat is equal to the buoyant force acting on the boat.
When the water in the barrel is poured overboard, the level of the swimming pool level would remain unchanged as the weight of the boat with the water and barrel would remain unchanged ( as the density and volume of the whole system remains same) and hence, the weight of the water (of the swimming pool) displaced by the boat would remain same.
A boat loaded with a barrel of water floats in a swimming pool. When the water in the barrel is poured overboard, the swimming pool level will <u>remain unchanged. </u>
Answer:x=23.4 cm
Explanation:
Given
mass of block 
inclination 
coefficient of static friction 
coefficient of kinetic friction 
distance traveled 
spring constant 
work done by gravity+work done by friction=Energy stored in Spring






Electric energy??? there isn't much information from the question but I can infer it's electricity.