kinetic energy is usually measured in joule J which is equals to kgm²/s²
Answer:
The total Mechanical energy will be zero
Explanation: Escape velocity is the velocity required by a free object in order to overcome the impact of the force of gravity. The total mechanical energy of an object is the total energy possessed by an object which includes its kinectic and potential energy.
since the object is moving at an escape velocity which is 11.2m/s the object will be assumed to be weightless
Etotal = kinetic energy + potential energy
kinetic energy= 1/2*M*V*V
Potential energy=MGH
Etotal=1/2*0*11.2*11.2+0*0*0
Etotal=0+0
Etotal=0.
Answer:
The lenses with different focal length are four.
Explanation:
Given that,
Radius of curvature R₁= 4
Radius of curvature R₂ = 8
We know ,
Refractive index of glass = 1.6
When, R₁= 4, R₂ = 8
We need to calculate the focal length of the lens
Using formula of focal length

Put the value into the formula



When , R₁= -4, R₂ = 8
Put the value into the formula



When , R₁= 4, R₂ = -8
Put the value into the formula



When , R₁= -4, R₂ = -8
Put the value into the formula



Hence, The lenses with different focal length are four.
The force applied to the cannonball and cannon is equal. The explosion inside the cannon will generate a pressure which will turn into a force on both cannonball and cannon. The cannon being heavier and fixed to the ground will move a bit, but the cannonball will be thrown away, fired.