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2) Izabela, a 10 year girl, asks for a red balloon for Christmas. Her father purchases a red balloon with ‘Merry Christmas Izzy’ written on it. Izabela blows the balloon into a 30.0 cm diameter balloon using helium gas. Assume the balloon is a sphere.
a. Determine the buoyant force on the balloon.
b. If the mass of the rubber balloon is 7.0 g, determine the net upward force on the balloon. Will the balloon rise?
You may assume that the density of helium is 1.28 kg/m3 and that .
2) A rocket is launched straight up from Earth’s surface at 2100 m/s.
a. By ignoring air resistance and considering the conservation of mechanical energy, determine the maximum height it reaches.
b. What other information would be required to solve this problem in part (a) if air resistance is not ignored? How would your answer in part (a) change?
2) A fire hose with inside diameter 12.7 cm is attached to a street-level hydrant where the water pressure is 515 kPa. The hydrant delivers water to the hose at 340 L/min. Firefighters have taken the nozzle of the hose to the third floor of a nearby building, 7.80 m above street level.
a. Determine the
i. volume flow rate of water delivered to the nozzle in
ii. flow speed into the hose.
iii. flow speed through the nozzle which has a diameter of 1.91 cm.
iv. pressure at the nozzle.
b. Comment on your answers to parts a(iii) and a(iv) for this particular application of fluid mechanics.
c. Determine the Reynolds number of the flow at the nozzle given that the density of water is
and its dynamic viscosity is at . Is the flow laminar?
1. A child starts sledding from rest, going down a 40 m long 7.5° incline, then coasting across a horizontal stretch. The mass of the sled + child is 35 kg, and the coefficient of kinetic friction is 0.060.
a. Make force diagrams for the sled + child on both the hill and the horizontal stretch.
b. Resolve the weight of the sled + child along and perpendicular to the plane.
c. Determine the reaction force on the sled + child.
d. Determine the speed of the sled + child at the bottom of the incline.
e. How far along the horizontal stretch does the sled + child travel before stopping?
h. Determine how much work is done on the sled + child by the gravitational force while the child + sled is moving along the incline.
i. By considering the energy of the system and energy transformations, determine the speed of the sled + child at the bottom of the incline. Does your answer agree with part d?
calculate the volume of the same mass of water at 300 degrees
Given that A=2i-3j+6k and B=i-2j+2k.find the scalar projection of B onto A
A boy throws a ball upwards giving it an initial speed of 15m/s.neglect air resistance. How long does the ball take too return to the boy's hand
an ideal heat engine has an efficiency of 50% when its low temperature reserver is 25°C. it is desire to increase the efficiency to 35%. what change should be made in either (1) the temperature of the low reserver or (2) the temperature of the high reserver??
A military aircraft is flying horizontally at a speed of 500m/s, drops a missile at an enemy target when it is at a height of 132.5m above the ground level.calculate in kilometers, the value of the horizontal distance travelled by the missile before hitting the target.[g= 10m/s square]
To sterilize a 50.0-g glass babby bottle, we must raise its temperature from 22.0 degree celcius to 95.0 degree celcius . How much heat transfer is required?
