2. A 38kg child is at the top of a slide that is 2.1m tall. (a) If there is no friction, how fast will they be moving when they reach the bottom of the slide?
(b) If they lose 250.0J of energy to sound, heat, and friction, how fast will they be moving when they reach the bottom?

3. A 0.850 kg air-track glider moving at 1.75 m/s bumps into a 1.45 kg glider initially at rest.
(a) If the collision is elastic, find the total kinetic energy after collision.
(b) If the collision is completely inelastic, find the total kinetic energy after collision.

In a wind tunnel the speed changes as the cross sectional area of the tunnel changes. if the speed in a 6' x 6' square test section is 100 mph, what was the speed upstream of the test section where the tunnel measured 20' x 20'? use conservation of mass and assume incompressible flow. conservation of mass requires that as the flow moves through a path or a duct the product of the density, velocity and cross sectional area must remain constant; i.e., that ova-constant. a model is being tested in a wind tunnel at a speed of 100 mph if the flow in the test section is at sea level standard conditions, what is the pressure at the model's stagnation point? (a) the tunnel speed is being measured by a pitot-static tube connected to a u- tube manometer. what is the reading on that manometer in inches of water? (b) at one point on the model a pressure of 2058 psf is measured. what is the local airspeed at that point?

Estimate the kinetic energy of the neptune with respect to the sun as the sum of the terms, that due to its daily rotation about its axis, and that due to its yearly revolution about the sun. [assume the neptune is a uniform sphere with mass = 1.0×1026 kg , radius = 2.5×1010 m , rotation period 16.1 h , orbital period 6.01×104 d and is 4.6×109 km from the sun.]

Aman jogs at a velocity of 2.5 m/s west for 1,200 s. he then walks at a velocity 1.0 m/s east for 500 s and then stops to rest . what is the displacement of man when he stops to rest?