Answer:
when the body is resting N = 246.96 N
when the body is resting on a tilted surface N = 212.12 N.
when the body is in a elevator N = 317.036 N
Explanation:
when the block is resting on a stationary surface the normal force is balanced by the weight of the body.
weight of the body = mg = 25.2×9.8 = 246.96 N
therefore normal force = 246.98 N.
when the block is resting on a tilted surface the normal force will be balanced by the 
component of the weight where Ф is the angle of inclination.
therefore N = mg
N= 212.12 N.
when the block is resting on a elevator that is accelerated upward the normal force will be the sum of weight and force due to acceleration ma
therefore N = 246.98 + 25.2×2.78
N = 317.036 N
Answer:
<em>The minimum pressure car tire pressure is 300,000 Pa</em>
Explanation:
<u>Pressure</u>
It's a measure of the force exerted by an object per unit surface:
Where F is the force applied on a surface area A.
We are given the total weight of a car with passengers as Ft=30,000 N and we also know the area of contact of each tire with the ground as 
.
The minimum pressure each tire can have is when the total weight is evenly distributed in all four tires, thus F=Ft/4=7,500 N.
Calculating the pressure:
P=300,000 Pa
The minimum pressure car tire pressure is 300,000 Pa
if spring constant is doubled, the mass on spring will be doubled as well. according to this formula, F=ke
k stands for spring constant and e stands for the length extended
Your answer would be 0.20 Hz
