Answer:
Time, t = 0.87 seconds
Explanation:
Given that,
Initial velocity of the object, u = 4.3 m/s
The coefficient of kinetic friction between horizontal tabletop and the object is 0.5
We need to find the time taken by the object for the object to come to rest i.e. final velocity will be 0.
Using first equation of motion to find it as :
a is the acceleration, here,
So, the time taken by the object to come at rest is 0.87 seconds. Hence, this is the required solution.
Complete Question
The light energy that falls on a square meter of ground over the course of a typical sunny day is about 20 MJ . The average rate of electric energy consumption in one house is 1.0 kW .
If light energy to electric energy conversion using solar cells is 12 % efficient, how many square miles of land must be covered with solar cells to supply the electrical energy for 350000 houses? Assume there is no cloud cover.
Answer:
The area is
Explanation:
From the question we are told that
The efficiency is 12%
The number of houses is
The light energy per day is
The average rating of electric energy for a house is
Generally the electric energy which the solar cells covering produces in a day is
Energy for required by one house for one day is
Energy needed for 350000 house is
The area covered is mathematically represented as