<span>A large body of air hats has similar properties of a temperature and moisture is an air mass.</span>
The speed of bullet =
850 m/s
Distance given = 1 km = 1000m
S = D/t
t • S = D/t • t
St = D
St/S = D/S
t = D/S
t = 1000m/850m/s
t = 1.176 s
It will take the bullet 1.176 or about 1.18 seconds to go 1 km.
Answer: a) 3.85 days
b) 10.54 days
Explanation:-
Expression for rate law for first order kinetics is given by:

where,
k = rate constant = ?
t = time taken for decomposition = 3 days
a = let initial amount of the reactant = 100 g
a - x = amount left after decay process = 
First we have to calculate the rate constant, we use the formula :
Now put all the given values in above equation, we get


a) Half-life of radon-222:


Thus half-life of radon-222 is 3.85 days.
b) Time taken for the sample to decay to 15% of its original amount:
where,
k = rate constant = 
t = time taken for decomposition = ?
a = let initial amount of the reactant = 100 g
a - x = amount left after decay process = 


Thus it will take 10.54 days for the sample to decay to 15% of its original amount.
Answer:
IMA = 2.5 metres
EFFICIENCY = 80%
Explanation:
The AMA of a machine is referred to as the Actual Mechanical Advantage of a machine, calculated as the ratio of the output to the input force.
The Ideal Mechanical Advantage is the ratio of the input distance to the output distance.
From the diagram, the input distance which is also the distance moved by effort = 5metres
The load distance (output distance) = 2 metres
IMA = INPUT DISTANCE / OUTPUT DISTANCE
IMA = 5metres / 2 metres = 2.5 meters
Efficiency is the ratio of AMA TO IMA
AMA = 2, IMA = 2.5
EFFICIENCY = AMA / IMA
EFFICIENCY = (2 / 2.5) × 100%= 0.8 × 100%
EFFICIENCY = 80%