A worker uses an inclined plane to do the work of moving a wheelbarrow load up to a higher level rather than lifting the wheelbarrow straight up. Which of the following choices best describes his decision to use an inclined plane? *
5 points
He uses less effort force and was able to move the wheelbarrow the same distance.
He uses less effort force but had to move the wheelbarrow a greater distance.
He uses more force but moved the wheelbarrow over a shorter distance.
He uses the same effort force but moved the wheelbarrow the same distance.

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.

Suppose a comet has an orbital period of 309.1 years around the sun. what is it’s average distance from the sun?

Which is an advantage of subdividing science into different areas?