Answer:
4 J
Explanation:
From the image attached, we can see 2 horizontal forces acting on the box albeit in opposite directions.
Now, the net force will be;
F_net = 3 - 1
F_net = 2 N
To move a distance of 2 metres, kinetic energy is;
K.E = Force × Distance = 2 × 2 = 4 J
Mgraphs are proportional ofrelationships
Correct option is=A
because 25mph means=25miles per hour
Answer: a) 5 x 10^5 kg/s b) 444 MW
Explanation:
Kinetic energy per unit mass Ke is
Ke = V^2 / 2
Ke = 3^2 / 2 = 4.5 J/kg = 0.0045 kJ/kg
Now potential energy per unit mass Pe is
Pe = g x z = 9.8 x 90 = 882.9 J/kg = 0.8829 kJ/kg
The total mechanical energy of the River per unit mass e = Ke + Pe = 0.0045 + 0.8829 = 0.88744 J/kg
M = P x V = 1000 x 500 = 5 x 10^5 kg/s
b) power generation potential of the entire river at the location Wmax = Emech = M x Emech = 500,000 x 0.88744 = 444,000kW = 444MW
kinematic equation
v^2=u^2+2*a*s
7.4^2=8^2-2*5.6^2*width
(7.4^2-64)/(2*5.6^2)=-width