Bob is designing two new bicycles. The bikes are identical except for the wheels. Bike 1 has solid wheels, mass M, radius R. Bike 2 has "hoop" wheels. The hoop wheels have the same mass, but that mass is situated as far as possible from the center. Bob has decided to take each bicycle for a test ride. Assume Bob exerts the same effort to get each bicycle moving. Which bicycle will take longer to build up speed? Briefly explain/justify your answer with appropriate physics concepts.

Um vetor representa um deslocamento cujo módulo é 20 m. se v faz um ângulo de 60 graus com a horizontal, qual é o valor das componentes horizontal e vertical deste vetor?

Electric field of the earth. the earth has a net electric charge that causes a field at points near its surface equal to 150 n> c and directed in toward the center of the earth. (a) what magnitude and sign of charge would a 60-kg human have to acquire to overcome his or her weight by the force exerted by the earth’s electric field? (b) what would be the force of repulsion between two people each with the charge calculated in part (a) and separated by a distance of 100 m? is use of the earth’s electric field a feasible means of flight? why or why not?

Aturntable that spins at a constant 74.0 rpm takes 3.10 s to reach this angular speed after it is turned on. find its angular acceleration (in rad/s2), assuming it to be constant, and the number of degrees it turns through while speeding up.