Answer:
4.3 m/s
Explanation:
a = rate at which the automobile loses speed = - 7.2 m/s²
v₀ = initial maximum speed of automobile
t' = reaction time for applying the brakes = 0.55 s
d = distance available for stopping the vehicle = 3.6 m
d' = distance traveled while applying the brakes = v₀ t' = (0.55) v₀
v = final speed after the vehicle comes to stop = 0 m/s
Using the equation
v² = v₀² + 2 a (d - d' )
0² = v₀² + 2 (- 7.2) (3.6 - (0.55) v₀)
v₀ = 4.3 m/s
Answer: The released electromagnetic wave will travel in +y direction
Explanation:
It should be noted that, in a situation, whereby an excited hydrogen atom releases an electromagnetic wave to return to its normal state. And it's also evident that the futuristic dual electric/magnetic field tester on the electromagnetic wave to find the directions of the electric field and magnetic field is used. Eventually, your device tells you that the electric field is pointing in the positive y direction and the magnetic field is pointing in the positive x direction. Therefore, the released electromagnetic wave will travel in +y direction.
The charge density of the sheet is 1.384×10⁻⁷C/m².
Charge density is defined as the charge per unit area.
The sheet is a square of length l=17 cm.
Calculate the area A of the sheet .

The charge Q on the sheet is

The charge density σ is given by,

Substitute 4×10⁻⁹C for Q and 0.0289 m² for A.

Thus, the charge density of the sheet is <u>1.384×10⁻⁷C/m².</u>
Answer:
2.98 second
Explanation:
The severity index is defined by :

a is dimensionless constant that equals the number of multiples of g
Conditions are given as :
Initial velocity, u = 0
Acceleration, a = 34 m/s²
Final velocity, v = 16.4 km/h = 4.56 m/s
We can find t from the above data as follows :

As a is the acceleration that is multiple of g.
So,

So,
Severity index,

Hence, the severity index for the collision is 2.98 seconds.
Answer:
Explanation:
Given
average speed of Phelps 
total distance 
he swims first 100 m at an average speed if 
so time taken is 
suppose
is the time taken to swim remaining half
average velocity is 



so velocity in the second half is
