Henry will lift 200 N load 20 m up a ladder in 40 s. While the Ricardo will take 400 N load in 80 seconds. So, For Henry to take 400 N load it will take him 80 seconds in two attempts. And,also, he will have to cover 40 m of distance.
Answer:
2.5 m/s
Explanation:
Mechanical energy is the sum of the potential and kinetic energy.
E = PE + KE
E = mgh + ½mv²
172.1 J = (7.26 kg) (9.8 m/s²) (2.1 m) + ½ (7.26 kg) v²
v = 2.5 m/s
Disagree
Explanation:
Fluoresce objects will glow when put under Ultraviolet light as the molecules are excited by the ultraviolet radiation.
Microwaves give micro-waves that are present in another spectrum of wave length and will not be able to fluoresce the molecules
Answer:
The current needed to transmit Power of 4 W is 28.47 A
Solution:
As per the question:
Length of the antenna, 
Frequency, 
Power transmitted, 
Now,
For a monopole antenna:

where
= wavelength transmitted by the antenna
c = speed of light in vacuum

Now,
Since, the value of
>>
thus the monopole is a Hertian monopole.
The resistance is calculated as:




Now, the current I is given by:

Answer:
a) t=10.2s
b) The 2g-cube moves first
Explanation:
Since the electric force is the same on both cubes and so is the coefficient of static friction, the first one to move will be the one with less mass.
So, on the 2g-cube the sum of forces are:

Replacing the friction on the first equation:
Thus 
The electric force is:
Solving for q:
q=71.44nC
This amount divided by the rate at which they are being charged:
t = 71.44nC / 7nC/s = 10.2s