First you need to find the initial x component which is 13.02. After that you plug it into the 3rd formula on the AP physics formula sheet. Then rearrange it into the quadratic formula and solve for time. The answer should be 4.1 seconds.
K=0.5 mu×u
K=2200J no matter the direction
Answer:
b. 
Explanation:
As we know that the electric field due to infinite line charge is given as

here we can find potential difference between two points using the relation

now we have

now we have

now plug in all values in it


now we know by energy conservation


Answer:
15.07 ksi
Explanation:
Given that:
Pitch (P) = 5 teeth/in
Pressure angle (
) = 20°
Pinion speed (
) = 2000 rev/min
Power (H) = 30 hp
Teeth on gear (
) = 50
Teeth on pinion (
) = 20
Face width (F) = 1 in
Let us first determine the diameter (d) of the pinion.
Diameter (d) =
=
= 4 in
From the values of Lewis Form Factor Y for (
) = 20 ; at 20°
Y = 0.321
To find the velocity (V); we use the formula:


V = 2094.40 ft/min
For cut or milled profile; the velocity factor
can be determined as follows:


= 2.0472
However, there is need to get the value of the tangential load
, in order to achieve that, we have the following expression




Finally, the bending stress is calculated via the formula:



15.07 ksi
∴ The estimate of the bending stress = 15.07 ksi