Explanation:
momentum = mass x velocity
initial momentum = 100 x 15 = 1500kgm/s
after momentum = 100 x 20 = 2000kgm/s
a =(v-u)/t
a = (20-15)/10
a = 5/10
a = 0.5m/s²
f = ma
f = 100 x 0.5
f = 50N
Answer:
The statement is true: velocity and acceleration have opposite directions in the interval of braking.
Explanation:
Let's say we have a velocity
.
The acceleration
is the rate of change of the velocity
. This means that if
is <em>increasing during</em> time, then
must be positive. But if
is <em>decreasing over</em> time, then
will be negative (even though the velocity is positive).
Mathematically:

decreases ⇒
⇒
.
Example:

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:
The answer to your question is Alpha particles.
Explanation: An electron released by a radioactive nucleus that causes a neutron to change into a proton is called a beta particle.
Energy is neither created nor destroyed
E in = E out
750 J in so 750 J out