Dear Sir/Mam,

I have doubts in the following physics questions in the below attached image.

Yours,

Hridith Sudev

(a) Footballers wear shoes with studs so as to increase the grip. Any normal shoe has a decent grip on the a football pitch but the footballers thrive for more grip. Why so? The reason is that they have to suddenly start and stop their run at many instances which may result into slipping.Hence, they use spikes which gets embedded into the soft grass pitch for a while to give them sudden start and sudden stop. The same ius used by Athletes, Hockey players, Cricket players and many other players of field sports.

(b) Single roller blades are faster better than double roller blades skates because of the fact that the single roller blades skates allow the rider to bend moreas the part of foot above the blade have more space to facilitate the bending of foot which inturn allows bending of body. In case of double blades skates this bending is restricted because there is not much space available for bending.
The bending of rider’s body allows the rider to make a sharp turn and also which high speed.

(C) It is easier to ride the bicycle with larger wheels because in pedalling with the same speed(same angular velocity), the translation speed will be greater for bigger wheel bicycle.Same effort high speed or less effort from bigger wheel bike and more effort from smaller wheels bike and same speed.