When the velocity increases, then the acceleration will be positive and when the velocity decrease then the acceleration will be negative.
During the first hour, the velocity was 70 mph and during the seconds hour the velocity was 60 mph. Hence, the velocity decrease in the seconds hour. So, the acceleration will be negative during the second hour.
Now, during the third hour the velocity increases as it is 80 mph. Hence, the acceleration will be positive during the third hour.
Microwaves are a type of wave that are sandwiched between radio waves and infrared radiation on the electromagnetic spectrum. In the case of microwave ovens, the commonly used wave frequency is roughly 2,450 megahertz (2.45gigahertz).
Answer:
Stella is driving down a steep hill. She should keep her car in a lower gear to help slow her vehicle.
Explanation:
Answer:
<em>Speed of the electron is 2.46 x 10^8 m/s</em>
<em></em>
Explanation:
momentum of the electron before relativistic effect = 
where
is the rest mass of the electron
V is the velocity of the electron.
under relativistic effect, the mass increases.
under relativistic effect, the new mass M will be
M = 
where

c is the speed of light = 3 x 10^8 m/s
V is the speed with which the electron travels.
The new momentum will therefore be
==> 
It is stated that the relativistic momentum is 1.75 times the non-relativistic momentum. Equating, we have
1.75
= 
the equation reduces to
1.75 = 
square both sides of the equation, we have
3.0625 = 1/
3.0625 - 3.0625
= 1
2.0625 = 3.0625
= 0.67
β = 0.819
substitute for 
V/c = 0.819
V = c x 0.819
V = 3 x 10^8 x 0.819 = <em>2.46 x 10^8 m/s</em>