The atmospheric pressure on a particular day was measured as 750 mm of mercury. Convert this pressure measurement to Pascal. (Assume the density of mercury to be 13 600 kg/m3 and the acceleration due to gravity is 10 N/kg (ms-2). ​

Ablock of mass m = 2.5 kg is attached to a spring with spring constant k = 710 n/m. it is initially at rest on an inclined plane that is at an angle of θ = 23° with respect to the horizontal, and the coefficient of kinetic friction between the block and the plane is μk = 0.19. in the initial position, where the spring is compressed by a distance of d = 0.16 m, the mass is at its lowest position and the spring is compressed the maximum amount. take the initial gravitational energy of the block as zero. a) what is the block's initial mechanical energy? b) if the spring pushes the block up the incline, what distance, l, in meters will the block travel before coming to rest? the spring remains attached to both the block and the fixed wall throughout its motion.

When the force acting on an object points at least partially in the direction of the motion the work done is considered to be negative

What are similarities and differences of reflection, refraction, diffraction and absorption?