Police investigators, examining the scene of an accident involving two cars, measure 77 m -long skid marks of one of the cars, which nearly came to a stop before colliding. The coefficient of kinetic friction between rubber and the pavement is about 0.80. Estimate the initial speed of that car assuming a level road.

Athin, square metal plate measures 14 cm on each side and has emissivity of 0.60. the plate is heated to a temperature of 745°c. what is the rate at which the plate radiates energy ? the stefan-boltzmann constant is 5.67 × 10-8 w/(m2 ? k4). remember that the plate will radiate energy from both its top and bottom surfaces.

In what direction does the medium move relative to the direction of the wave? explain.

Eddy whose mass is 55kg climbs up the 1.50 meter high stairs in 2s.calculate eddy’s power rating