7. Valentina, the Russian Cosmonaut, goes outside her ship for a space walk, but when she is floating motionless, 15 m from the ship, her tether catches on a sharp piece
of metal and is severed. Valentina tosses her 2.0 kg camera away from the
spaceship with a speed of 12 m/s.
a. How fast will Valentina, whose mass is now 68 kg, travel toward the spaceship?
b. Assuming the spaceship remains at rest with respect to Valentina, how long will
it take her to reach the ship?
2

We want to calculate the total metabolic heat generated by a singing canary taking into account heat transfer by radiation, convection and exhaling air. the air temperature is 20 oc, canary’s body internal and surface temperature is 33oc, external body surface convective heat transfer coefficient is 25.2 w/m2 .k, temperature difference between the inhaled and exhaled air is 4.3 oc, the ventilation rate is 0.74 cc of air per second, specific heat of air is 1.0066 kj/kg. k and density of air is 1.16 kg/m3 . assume the canary’s body to be a cylinder with 7 cm diameter and 9 cm length, and heat exchange is from the side as well as the top and bottom of cylinder. calculate 1) the net rate of heat lost by radiation, assuming heat gained by the bird through radiation from the surroundings is 11.5 w; 2) rate of heat transferred by convection to the surrounding air; 3) rate of heat transferred in the exhaling air without considering any internal evaporation; 4) total metabolic power.

Debbie places two shopping carts in a cart corral she pushes the first cart which then pushes a second cart what force is being exerted

Apulley with mass mp and a radius rp is attached to the ceiling, in a gravity field of 9.81 m/s2 and rotates with no friction about its pivot.