Select the one which is different from the others in the manner it is applied

Options

A. Electrostatic force
B. Frictional force
C. Gravitational force
D. magnetic force

Answer

B

Explanation

Time taken by the bus to cover 10 km,
`t_(1)=(10)/(40)=(1)/(4)h`
Time taken by the bus to cover
Remaining 45km,
`t_(2)=(45)/(60)=(3)/(4)h`
Average speed=`("Total distance covered")/("Total time "(t_(1)+t_(2)))`
`=(10+45)/(((1)/(4)+(3)/(4)))=55km//h`