Answer:
t = 1.58 s
Explanation:
given,
Speed of ranger, v = 56 km/h
v = 56 x 0.278 = 15.57 m/s
distance, d = 65 m
deceleration,a = 3 m/s²
reaction time = ?
using stopping distance formula


t is the reaction time

t = 1.58 s
hence, the reaction time of the ranger is equal to 1.58 s.
Answer:
F = 1,875 N
Explanation:
force=

∆H = m∆V
where ∆H ----> change in momentum.
( final momentum - initial momentum )
and ∆V ----> change in velocity
( final velocity - initial velocity )
and m ----> is mass
then f =

= 1,875 N
Answer: d₂ = 170 mGya
Explanation:
the relationship between absonbed 'd' and exposure 'E' is given as;
D(Gv) = F . x (AS/xB)
F is a conversion coefficient depending on medium
so we can simply write
d₁/d₂ = x₁/x₂
Given that;
our x₁ = 60 mAs, x₂ = 120 mAs, d₁ = 85 mGya, d₂ = ?
from the given formula,
d₂ = (x₂d₁ / x₁)
now we substitute
d₂ = (120 × 85) / 60
d₂ = 170 mGya
∴ if 120 mAa is used, the new exposure will be 170 mGya
Answer:
Coefficient of friction will be 0.296
Explanation:
We have given initial speed of the stone u = 8 m /sec
It comes to rest so final speed v = 0 m /sec
Distance traveled before coming to rest s = 11 m
According to third equation of motion

So 

Acceleration due to gravity 
We know that acceleration is given by

So 

So coefficient of friction will be 0.296