An eager scientist on a hot summer day needs to determine how much ice to buy. She has a cooler which is filled with 36 cans of soda at a temperature of 82.9∘F. Each can has a mass of 375 g. The scientist wants the temperature of the drinks to be 40.1∘F. If there is no heat lost by the cooler and ignoring any heat lost to the soda containers, what mass ice of ice needs must she add to her cooler? Assume the temperature of the ice is 32.0 ∘F. The latent heat of fusion for ice is 80.0 cal/g, the specific heat of water is 1.00 cal/g·∘C, the specific heat of the soda is 0.900 cal/g·∘C, and there are 454 grams per pound.

013222

52222222222222222222222222222222222

explanation:

force is mass*acceleration.

we have a very small mass: 11.4*0.001 kg

if we want 0.035n of force, we need an acceleration:

0.035 = 11.4*0.001*a

a = 0.035/(11.4*0.001) m/s^2

d. air pressure decreases as altitude increases.

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s