Answer:
Non-zero digits are always significant
Answer:

Explanation:
Given that:
Half life = 30 min
Where, k is rate constant
So,
The rate constant, k = 0.0231 min⁻¹
Using integrated rate law for first order kinetics as:
Where,
is the concentration at time t
is the initial concentration
Given that:
The rate constant, k = 0.0231 min⁻¹
Initial concentration
= 7.50 mg
Final concentration
= 0.25 mg
Time = ?
Applying in the above equation, we get that:-

Answer:
F = 50000 N
Explanation:
The acceleration is rate of change of velocity of an object with respect to time.
Formula:
a = Δv/Δt
a = acceleration
Δv = change in velocity
Δt = change in time
Units:
The unit of acceleration is m.s⁻².
Acceleration can also be determine through following formula,
F = m × a
a = F/m
Given data:
Mass of car = 1250 Kg
Acceleration = 40 m/s².
Force = ?
Solution:
F = m × a
F = 1250 Kg × 40 m/s²
Kg.m/s² = N
F = 50000 N