Answer:
Velocity of truck will be 20.287 m /sec
Explanation:
We have given mass of the truck m = 4000 kg
Radius of the turn r = 70 m
Coefficient of friction 
Centripetal force is given 
And frictional force is equal to 
For body to be move these two forces must be equal
So 

The answer is d hope this helps
Cars are the mechanical device which convert chemical energy of fuel into mechanical energy, the engine used in the automobiles car are very inefficient, they can only convert 30-40% of chemical energy of fuel into mechanical energy, since thermodynamics is the branch of science that deals with the conversion of energy, thus due to poor conversion rate of chemical energy into mechanical energy, cars are known as inefficient machine.