Friction can be a useful force because it prevents our shoes slipping on the pavement when we walk and stops car tyres skidding on the road.
Notuseful
Friction is sometimes unhelpful.
For example, if you don't lubricate your bike regularly with oil, the friction in the chain and axles increases. Your bike will be noisy and difficult to pedal. When there is a lot of friction between moving parts, energy is lost to the surroundings as heat.
Answers & Comments
Answer:
Useful
Friction can be a useful force because it prevents our shoes slipping on the pavement when we walk and stops car tyres skidding on the road.
Not useful
Friction is sometimes unhelpful.
For example, if you don't lubricate your bike regularly with oil, the friction in the chain and axles increases. Your bike will be noisy and difficult to pedal. When there is a lot of friction between moving parts, energy is lost to the surroundings as heat.
Explanation:
Hope it helps!