Una viga metálica uniforme de longitud L= 4 m pesa 100 N y sostiene un objeto de 225 N como se muestra en la figura 4. Calcule la magnitud de las fuerzas que ejercen sobre la viga las columnas de apoyo colocadas en los extremos. Suponga que las longitudes son exactas.

What must be the same for any two resistors that are connected in series ? a. the potntial diffrence across each b. the rate at which charge moves through each c. the rate at which energy is used by each d. the resistance to the flow of charge of each

The ultracentrifuge is an important tool for separating and analyzing proteins. because of the enormous centripetal accelerations, the centrifuge must be carefully balanced, with each sample matched by a sample of identical mass on the opposite side. any difference in the masses of opposing samples creates a net force on the shaft of the rotor, potentially leading to a catastrophic failure of the apparatus. suppose a scientist makes a slight error in sample preparation and one sample has a mass 10 mg larger than the opposing sample. if the samples are 12 cm from the axis of the rotor and the ultracentrifuge spins at 70,000 rpm, what is the magnitude of the net force on the rotor due to the unbalanced samples? ( be thorough on your answer)

Which of the following is the main energy source for the sun? a. fission of hydrogen b. fusion of hydrogen c. fusion of helium d. fission of iron