Solar Radiation, The Solar Wind, and Gamma Ray Bursts
The answer to the question is C
In order to compare the two temperatures, we need to convert 20°F into Celsius. The formula we need to use is:
Substituting 20°F, we find
And this is less than 0°C, so the answer is
20°F is colder than 0°C.
Answer:
807.88N/m
Explanation:
<em>The question has some missing details in it, nevertheless, based on the given data we want to find the spring constant K</em>
Step one
given data
Unstretched length = 33.5 cm
Final length of the spring = 42.0 cm
Δx= 42-33.5
Δx=8.5cm to m= 0.085m
mass m= 7kg
The force on the spring
F=mg
F= 7*9.81
F=68.67N
Step two:
From Hooke's law, we can make k subject of formula and find the spring constant k, we have
F=kΔx---------1
make k subject of the formula
k=F/Δx
k= 68.67/ 0.085
k=807.88N/m
Answer:
1. 10.0 J
2. 0.742 m/s
3. 0.494 m/s
4. 0.0249 m
Explanation:
(1/4) The elastic energy in a spring is:
EE = ½ k x²
EE = ½ (502 N/m) (0.2 m)²
EE ≈ 10.0 J
(2/4) The energy in the spring is converted to kinetic energy in the block and work by friction.
EE = KE + W
EE = ½ m v² + Fd
10.0 J = ½ (8 kg) v² + (8 kg × 9.8 m/s² × 0.5) (0.2 m)
v ≈ 0.742 m/s
(3/4) Momentum is conserved.
Momentum before = momentum after
(8 kg) (0.742 m/s) = (8 kg + 4 kg) v
v ≈ 0.494 m/s
(4/4) The kinetic energy of the blocks is converted to work by friction.
KE = W
½ m v² = Fd
½ (8 kg + 4 kg) (0.494 m/s)² = ((8 kg + 4 kg) × 9.8 m/s² × 0.5) d
d ≈ 0.0249 m