Awatt is a measure of power (the rate of energy change) equal to 1 j> s. (a) calculate the number of joules in a kilowatt- hour. (b) an adult person radiates heat to the surroundings at about the same rate as a 100-watt electric incandescent light- bulb. what is the total amount of energy in kcal radiated to the surroundings by an adult in 24 h?

think its the third option

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