Answer:
6. 7870 kg/m³ (3 s.f.)
7. 33.4 g (3 s.f.)
8. 12600 kg/m³ (3 s.f.)
Explanation:
6. The SI unit for density is kg/m³. Thus convert the mass to Kg and volume to m³ first.
1 kg= 1000g
1m³= 1 ×10⁶ cm³
Mass of iron bar
= 64.2g
= 64.2 ÷1000 kg
= 0.0642 kg
Volume of iron bar
= 8.16 cm³
= 8.16 ÷ 10⁶
Density of iron bar
= 7870 kg/m³ (3 s.f.)
7.
Mass
= 1.16 ×28.8
= 33.408 g
= 33.4 g (3 s.f.)
8. Volume of brick
= 12 cm³
Mass of brick
= 151 g
= 151 ÷ 1000 kg
= 0.151 kg
Density of brick
= mass ÷ volume
(3 s.f.)
Answer:
2.28
Explanation:
HCl(l) ===> H+ + cl-
HCl is a very strong acid. Almost all of it will decompose to the right. That means the concentration of H+ is 0.00530
pH = - log [H+]
pH = - log[0.00530]
pH = - - 2.2757
pH = 2.2757
Rounded this 2.28
Answer: The momentum of the child and milk together is 58.125 kg.m/s
Explanation:
Momentum is defined as the product of object's mass and velocity.
Mathematically,
where, p = momentum
m = mass of the object
v = velocity of the object
In the given question, we are given that a child of mass 21.0 kg is carrying a gallon of milk having mass 2.25 kg and running with a velocity of 2.5 m/s. Hence, the momentum by both milk and child will be:
....(1)
Given:
Putting values in equation 1, we get:
Hence, the momentum of the child and milk together is 58.125 kg.m/s
They are both sources of power for objects that people use.
Explanation:
1. neutrons
2. protons
3. protons and neutrons
4. neutrons
5. electrons
I'm not sure with 1 and 4, sorry :<
