Answer:
The particle’s velocity is -16.9 m/s.
Explanation:
Given that,
Initial velocity of particle in negative x direction= 4.91 m/s
Time = 12.9 s
Final velocity of particle in positive x direction= 7.12 m/s
Before 12.4 sec,
Velocity of particle in negative x direction= 5.32 m/s
We need to calculate the acceleration
Using equation of motion


Where, v = final velocity
u = initial velocity
t = time
Put the value into the equation


We need to calculate the initial speed of the particle
Using equation of motion again


Put the value into the formula


Hence, The particle’s velocity is -16.9 m/s.
Answer:

vector with direction equal to the axis X.
Explanation:
We use the Gauss Law and the superposition law in order to solve this problem.
<u>Superposition Law:</u> the Total Electric field is the sum of the electric field of the first infinite sheet and the Electric field of the second infinite sheet:

<u>Thanks Gauss Law</u> we know that the electric field of a infinite sheet with density of charge σ is:

Then:

This electric field has a direction in the axis perpendicular to the sheets, that means it has the same direction as the axis X.
Explanation:
Given that,
Initial speed of the car, u = 88 km/h = 24.44 m/s
Reaction time, t = 2 s
Distance covered during this time, 
(a) Acceleration, 
We need to find the stopping distance, v = 0. It can be calculated using the third equation of motion as :


s = 74.66 meters
s = 74.66 + 48.88 = 123.54 meters
(b) Acceleration, 


s = 37.33 meters
s = 37.33 + 48.88 = 86.21 meters
Hence, this is the required solution.
Determined the displacement of a plane is 66 m:s
Answer:
D
Explanation:
Work is not a vector but it is a scalar