The answer should be C.
Ratio it has two radioactive isotopes is compared by overtime.
Hope it helped you.
-Charlie
The basis for Rutherford's Planetary model, was the results he got from experiments.
He observed that most of the alpha particles he fired at a gold foil, passed through the foil, but only few were deflected back. So he concluded that most of the Atom would be empty space, with a positive entity at the center.
Semiconductors are substances with properties somewhere between them. Conductors such as gold, silver and copper have low resistance and conduct electricity easily.
Answer:
a) Andrea's initial momentum, 200 kg m/s
b) Andrea's final momentum, 0
c) Impulse, = - 200 Ns
d) The force that the seat belt exerts on Andrea, - 400 N
Explanation:
Given data,
The initial velocity of the car is, u = 40 m/s
The mass of Andrea, m = 50 kg
The time period of deceleration, a = 0.5 s
The final velocity of the car, v = 0
a) Andrea's initial momentum,
p = mu
= 50 x 40
= 200 kg m/s
b) Andrea's final momentum
P = mv
= 50 x 0
= 0 kg m/s
c) Impulse
I = mv - mu
= 0 - 200
= - 200 Ns
The negative sign indicated that the momentum is decreased.
d) The force that the seat belt exerts on Andrea
F = (mv - mu)t
= (0 - 200) / 0.5
= - 400 Ns
Hence,the force that the seat belt exerts on Andrea is, - 400 N
Answer:
25.2 cm
Explanation:
K = 1050 N/m
m = 1.95 kg
h = 1.75 m
By the conservation of energy, the potential energy of the block is converted into the potential energy stored in the spring
m g h = 1/2 x k x y^2
Where, y be the distance by which the spring is compressed.
1.95 x 9.8 x 1.75 = 1/2 x 1050 x y^2
33.44 = 525 x y^2
y = 0.252 m
y = 25.2 cm
