Question

The crank and connecting rod of a petrol engine are 60 mm and 270 mm respectively. The net force on the piston when the crank has turned ${20}^o$ from the top dead centre is 2280 N. The thrust on the cylinder walls is

• A. 120 N
• B. 60 N
• C. 174 N
• D. 280 N

Answer 1

The correct option is C 174 N

$Given,\theta ={20}^o$,

$n=\frac{270}{60}=4.5$

$F_{net}=2280$

$sin\beta =\frac{sin\theta }{n}=\frac{sin2\theta }{4.5}$

$or\beta =4.36$


Thrust on the cylinder wall $=Ftan\beta$
= 2280 tan 4.36
= 173.8 N