Choices 'C' and 'D' are both correct.
(Except in 'C', changing the temperature from 1°C to 3°C is not usually
described as 'cooling', and it's not the water's 'mass' that changes. But
water does contract in volume during that change.)
Answer:

Explanation:
From the question we are told that:
Mass 
Drop distance 
Generally the equation for Spring Constant is mathematically given by



Answer:
Given:
radius of the coil, R = 6 cm = 0.06 m
current in the coil, I = 2.65 A
Magnetic field at the center, B =
Solution:
To find the number of turns, N, we use the given formula:

Therefore,

N = 22.74 = 23 turns (approx)
(a) The spring stiffness constant of the spring is 18,392 N/m.
(b) The time the car was in contact with the spring before it bounces off in the opposite direction is 0.23 s.
<h3>Kinetic energy of the car</h3>
The kinetic energy of the car is calculated as follows;
K.E = ¹/₂mv²
K.E = ¹/₂ x 950 x 22²
K.E = 229,900 J
<h3>Stiffness constant of the spring</h3>
The stiffness constant of the spring is calculated as follows;
K.E = U = ¹/₂kx²
k = 2U/x²
k = (2 x 229,900)/(5)²
k = 18,392 N/m
<h3>Force exerted on the spring</h3>
F = kx
F = 18,392 x 5
F = 91,960 N
<h3>Time of impact</h3>
F = mv/t
t = mv/F
t = (950 x 22)/(91960)
t = 0.23 s
Learn more about spring constant here: brainly.com/question/1968517
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Answer:
B. It is too slow to observe directly
Explanation:
They move too slow to be able to observe how they move.
I hope it helps! Have a great day!
bren~