Answer:
m = 4.4 × 10³ kg
Explanation:
Given that:
The total yearly energy is 4.0 × 10²⁰ J
The amount of mass that provides this energy can be determined by using the formula:
E = mc²
where;
c = speed of light in free space = (3 × 10⁸)
4.0 × 10²⁰ = m × (3 × 10⁸)²

m = 4.4 × 10³ kg
Answer:
Check the explanation
Explanation:
1) Pressure acting on the plug = Patm + P
Pressure = Patm + rho*g*h (Here h = D2)
Pressure = 101325 + 1000*9.8*7
Pressure = 169925 Pa
so, Force = PA
Force = 169925*pi*0.0152
Force = 120.1 N
Answer:a) 34.5 N; b) 24.5 N; c) 10 N; d) 1J
Explanation: In order to solve this problem we have to used the second Newton law given by:
∑F= m*a
F-f=m*a where f is the friction force (uk*Normal), from this we have
F= m*a+f=5 Kg*2 m/s^2+0.5*5Kg*9.8 m/s^2= 34.5 N
then f=uk*N=0.5*5Kg*9.8 m/s^2= 24.5N
the net Force = (34.5-24.5)N= 10 N
Finally the work done by the net force is equal to kinetic energy change so
W=∫Force net*dr= 10 N* 0.1 m= 1J