1. Convert the following: a. 15.0 kg to N
b. 85.0 N to kg
c. 220 lb to N
d. 550 N to lb.
2. What force is needed to accelerate the stone of
mass 25.0 kg upward at 5.00 m/s2?
Draw a free body diagram.

3. A rocket that weighs 7850 N on the earth is fired.
The force of propulsion is 1.04 x 104 N.
a. Find the mass of the rocket.
b. The acceleration of the rocket
c. The velocity of the rocket at the end of 10.0 s.
d. The displacement at the end of the above time
frame ( 10.0 s)
4. A force of 15.0 N is necessary to keep the 4.0 kg
wooden block moving along a table top at a uniform
velocity . Calculate the co-efficient of friction.
5. A car moving on a high way has a mass of 400 kg.
The coefficient of friction between the tire and the
car is 0.2. What acceleration will a force of 2500 N
produce on the car?

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.

Agroup of monkeys is trying to cross the river in a rowboat. the maximum buoyant force on the rowboat is 2,000 n. the weight of the rowboat is 1,000 n. each monkey has a weight of 150 n. how many monkeys can safely cross in the rowboat at one time? explain your reasoning, including any calculations you used to find the answer.

Aproton is shot from the negative disk toward the positive disk. what launch speed must the proton have to just barely reach the positive disk?