Answer:32.24 s
Explanation:
Given
mass of runner (m)=51.8 kg
Constant acceleration(a)=
Final velocity (v)=5.47 m/s
Time taken taken to reach 5.47 m/s
v=u+at


Distance traveled during this time is


So remaining distance left to travel with constant velocity=153.57 m
thus time 

Total time=28.07+4.17=32.24 s
Answer:
R= 20 ohm
Explanation:
Given that
Current ,I = 6 A
Voltage difference ,ΔV = 120 V
Lets take resistance of the stem iron = R
We know that ,the relationship between current ,voltage difference and resistance is given as
ΔV = I R

Now by putting the values in the above equation we get

R= 20 ohm
Therefore the resistance of the steam will be 20 ohm.
Answer:
A
Explanation:
All of the frictions are the same, but weight always goes straight down so it can only be A or B. Since they are going down a slope, then the normal force must be sloped. A is the only one out of A and B with a sloped normal force, so it has to be A
Answer:
It is Conductivity because it is the measure of the ease.
Answer:
Simple machine: pair of tongs, seesaw and wheelbarrow
Compound machine: sewing machine, fishing rod and reel and crane.
Explanation:
Simple machine is the simplest device to use mechanical advantages. It has simplest mechanism to multiply the magnitude of force.
So, pair of tongs, seesaw and wheelbarrow are the example of simple machine because their mechanism is simplest.
Compound machine is a device that is made up of more than one simple machine.
so, sewing machine, fishing rod and reel and crane are example of compound machine because these devices shows more than one machine in it.
Thus, classification is as follows:
Simple machine: pair of tongs, seesaw and wheelbarrow
Compound machine: sewing machine, fishing rod and reel and crane.