Answer:

Explanation:
From the attached file diagram, the total force acting on the charged box is the downward weight and the repulsive force acting in opposite to the weight force . Hence we can write the total force as

When fixed,F=o
Hence

The value of the acceleration is 16.2m/s^2
Answer:
Approximately
, assuming friction between the vehicle and the ground is negligible.
Explanation:
Let
denote the mass of the vehicle. Let
denote the initial velocity of the vehicle. Let
denote the spring constant (needs to be found.) Let
denote the maximum displacement of the spring.
Convert velocity of the vehicle to standard units (meters per second):
.
Initial kinetic energy (
) of the vehicle:
.
When the vehicle is brought to a rest, the elastic potential energy (
) stored in the spring would be:
.
By the conservation of energy, if the friction between the vehicle and the ground is negligible, the initial
of the vehicle should be equal to the
of the vehicle. In other words:
.
Rearrange this equation to find an expression for
, the spring constant:
.
Substitute in the given values
,
, and
:

An increase in voltage causes the flow of electric current to INCREASE. An increase in resistance causes the flow of electric current to DECREASE.
100% right
Answer:
Please see below as the answer is self-explanatory.
Explanation:
- The visible range extends roughly from 400 nm (violet) to 700 nm (red).
- Below the violet is the ultra-violet spectrum (with higher energy) and above red, we have the infra-red spectrum.
- The wavelengths in the range of 650 to 690 nm have red as the dominant color.
Answer:
Pressure of woman will be 
Pressure of the elephant will be 
Explanation:
We have given that mass of the woman m = 80 kg
Acceleration due to gravity 
Diameter of shoes = 1 cm =0.01 m
So radius 
So area 
We know that force is given F = mg
So 
Now we know that pressure is given by 
Now mass of elephant m = 5500 kg
So force of elephant = 5500×9.8 = 53900 N
Diameter = 20 cm
So radius r = 10 cm
So area will be 
So pressure will be 