1. (C.) -Si- is silicone which at room temp is a solid and it's a hard crystalline Brittle rock basically...
2. And it will Be D. NOT C... i can't stand user's who throw out answers for free points....
Let the angle be Θ (theta)
Let the mass of the crate be m.
a) When the crate just begins to slip. At that moment the net force will be equal to zero and the static friction will be at the maximum vale.
Normal force (N) = mg CosΘ
μ (coefficient of static friction) = 0.29
Static friction = μN = μmg CosΘ
Now, along the ramp, the equation of net force will be:
mg SinΘ - μmg CosΘ = 0
mg SinΘ = μmg CosΘ
tan Θ = μ
tan Θ = 0.29
Θ = 16.17°
b) Let the acceleration be a.
Coefficient of kinetic friction = μ = 0.26
Now, the equation of net force will be:
mg sinΘ - μ mg CosΘ = ma
a = g SinΘ - μg CosΘ
Plugging the values
a = 9.8 × 0.278 - 0.26 × 9.8 × 0.96
a = 2.7244 - 2.44608
a = 0.278 m/s^2
Hence, the acceleration is 0.278 m/s^2
dimension = 30.0 m ✕ 15.0 m ✕ 5.0 m.
density = 1.20 kg/m3
(a)volume = lenght * breadth * height
= 30 * 15 * 5
= 2250 metre cube = 2.25 cubic meter
(b) mass of air = density * volume
mass of air = 1.2 * 2250
mass of air = 2700kg
weight = mass * 9.8
= 2700 * 9.8
= 26,460 N
- The definition of Density is the amount of matter in a given space, or volume
- Density = mass/volume
- units for density kg/m^3
- Density of water 1g/ml
- Salt water is denser that is why don't sink as easily.
To know more about density visit : brainly.com/question/15164682
#SPJ4
Answer:B
Explanation:Grote reber was the first scientist to map the milky way galaxy using radio waves.
