Answer:
mgh₁ + ½mv₁² = mgh₂ + ½mv₂²
Explanation:
Initial total energy = final total energy
PE₁ + KE₁ = PE₂ + KE₂
mgh₁ + ½mv₁² = mgh₂ + ½mv₂²
The upward force the table exerts on the ground!
Equal and opposite forces.
Answer:
VR = 
Explanation:
A machine is a device that can be used to overcome a load by the application of an effort through a pivot. Examples are: pulleys, wedge, screw jack, wheel and axle etc.
The wheel and axle is a simple device that can be used to lift a load through a height. Its velocity ratio (VR) can be determined by:
VR = 
Note that for a practical wheel and axle, the radius of the wheel is greater than the radius of the axle.
Answer:
Power factor of the AC series circuit is 
Explanation:
It is given that,
Impedance of the AC series circuit, Z = 60 ohms
Resistance of the AC series circuit, R = 30 ohms
We need to find the power factor of the circuit. It is given by :




So, the power factor of the ac series circuit is
. Hence, this is the required solution.