Answer:
The net force is 392N, pointing down.
Explanation:
The net force is the sum of all forces acting on the rock, namely the gravity ("+" acting downward) and the friction force due to air resistance ("-" acting upward):

The net force is 392N and pointing down (positive)/
Answer:=14,160 kJ
Explanation: Let m1 and m2 be the initial and final amounts of mass within the tank, respectively. The steam properties are listed in the table below
Specific Internal SpecificTemp Pressure Volume Energy Enthalpy Quality Phase
C MPa m^3/kg kJ/kg kJ/kg
1 260 4.689 0.02993 2158 2298 0.7 Liquid Vapor Mixture
2 260 4.689 0.0422 2599 2797 1 Saturated Vapor
The mass initially contained in the tank is m1 = V/v1
m1 =0.85 m^3 /0.02993 m^3 /kg
= 28.4 kg
The mass finally contained in the tank is
m2 =V2/v
= 0.85 m^3 /0.0422 m^3 /kg
= 20.14 kg
The heat transfer is then
Qcv = m2u2 − m1u1 − he(m2 − m1)
Qcv = (20.14)(2599) − (28.4)(2158) − (2797)(20.14 − 28.4) = 14,160 kJ
Answer:
The angular acceleration of the centrifuge is -231.74 rad/s².
Explanation:
Given that,
Angular speed = 3500 rev/min = 366 rad/s
We need to calculate the angular displacement
Using formula of angular displacement

Put the value into the formula


We need to calculate the angular acceleration
Using equation of motion




Hence, The angular acceleration of the centrifuge is -231.74 rad/s².
Based on the Newton's second law of motion, the value of the net force acting on the object is equal to the product of the mass and the acceleration due to gravity. If we let a be the acceleration due to gravity, the equation that would allow us to calculate it's value is,
W = m x a
where W is weight, m is mass, and a is acceleration. Substituting the known values,
40 kg m/s² = (10 kg) x a
Calculating for the value of a from the equation will give us an answer equal to 4.
ANSWER: 4 m/s².