Answer:
The speed of the block is 8.2 m/s
Explanation:
Given;
mass of block, m = 2.1 kg
height above the top of the spring, h = 5.5 m
First, we determine the spring constant based on the principle of conservation of potential energy
¹/₂Kx² = mg(h +x)
¹/₂K(0.25)² = 2.1 x 9.8(5.5 +0.25)
0.03125K = 118.335
K = 118.335 / 0.03125
K = 3786.72 N/m
Total energy stored in the block at rest is only potential energy given as:
E = U = mgh
U = 2.1 x 9.8 x 5.5 = 113.19 J
Work done in compressing the spring to 15.0 cm:
W = ¹/₂Kx² = ¹/₂ (3786.72)(0.15)² = 42.6 J
This is equal to elastic potential energy stored in the spring,
Then, kinetic energy of the spring is given as:
K.E = E - W
K.E = 113.19 J - 42.6 J
K.E = 70.59 J
To determine the speed of the block due to this energy:
KE = ¹/₂mv²
70.59 = ¹/₂ x 2.1 x v²
70.59 = 1.05v²
v² = 70.59 / 1.05
v² = 67.229
v = √67.229
v = 8.2 m/s
Answer:
The momentum of the photon is 1.707 x 10⁻²² kg.m/s
Explanation:
Given;
kinetic of electron, K.E = 100 keV = 100,000 eV = 100,000 x 1.6 x 10⁻¹⁹ J = 1.6 x 10⁻¹⁴ J
Kinetic energy is given as;
K.E = ¹/₂mv²
where;
v is speed of the electron

Therefore, the momentum of the photon is 1.707 x 10⁻²² kg.m/s
Answer:
Mechanical energy
Explanation:
Mechanical energy is needed for movement of objects. Muscles convert chemical energy provided by the rest of the body to allow movement.
In the reaction between 1 molecule of bromine and 2 molecules of potassium chloride, there are six atoms in the products.
Let's consider the balanced equation for the reaction between 1 molecule of bromine and 2 molecules of potassium chloride. This is a single replacement reaction.
Br₂ + 2 KCl ⇒ 2 KBr + Cl₂
We obtain as products, 2 molecules of potassium bromide and 1 molecule of chlorine.
- 1 molecule of KBr has 2 atoms, so 2 molecules contribute with 4 atoms.
- 1 molecule of Cl₂ has 2 atoms.
- The 4 atoms from KBr and the 2 atoms from Cl₂ make a total of 6 atoms.
In the reaction between 1 molecule of bromine and 2 molecules of potassium chloride, there are six atoms in the products.
Learn more: brainly.com/question/21850455
Answer:D
Explanation:
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