Difference between solid friction and viscosity is as follows: Viscosity is proportional to the surface area whereas solid friction is independent of area of solid surfaces in contact. Viscous force on the body depends upon its velocity in the viscous media. But, friction does not depend on the velocity of the body.
We know, F = k * q₁ * q₂ / r²
Substitute the known values,
F = 9 * 10⁹ * 5 * 7 / (1.2)²
F = 315 * 10⁹ / 1.44
F = 218.75 * 10⁹ N
F = 2.1875 * 10¹¹ N [ Final Answer ]
Hope this helps!
Explanation:
Given that,
Mass of the car, m₁ = 1250 kg
Initial speed of the car, u₁ = 7.39 m/s
Mass of the truck, m₂ = 5380 kg
It is stationary, u₂ = 0
Final speed of the truck, v₂ = 2.3 m/s
Let v₁ is the final velocity of the car. Using the conservation of momentum as :
So, the final velocity of the car is 2.5 m/s but in opposite direction. Hence, this is the required solution.
The energy bar eaten by Sheila has chemical energy locked up inside it. This chemical energy is converted to mechanical energy in form of potential and kinetic energy and this in turn is converted to heat energy as the run progresses. Thus, the energy changes are: chemical energy to mechanical energy [kinetic and potential] and finally to heat energy.
