A 45-kg boy pulls a wagon with a force of 38 N for a distance of 550 m. If the boy takes 240 s, what is the power expended by the boy? (Round your answer to two significant figures.)

Amass has an acceleration of 10- 2t. what is its velocity and displacement if it started at x- 4m and the initial velocity was 8m/s? at what time does it have 0 velocity? graph all graphs.

Starting with only the balmer series light (visible light), how could we ensure that the solar panels generate a current that mark can use for his power station? a)by gradually increasing the brightness (amount) of light that we shine on it. b)by gradually increasing the frequency of the light we shine on it. c)by gradually increasing the wavelength of the light that we shine on it.

Astudent pushes on a 20.0 kg box with a force of 50 n at an angle of 30° below the horizontal. the box accelerates at a rate of 0.5 m/s2 across a horizontal floor. what is the value of the normal force on the box? 200 n 243 n 156 n 225 n