Answer:
12g/cm³
Explanation:
Given parameters:
Mass of the metal = 1200g
Volume of water in the measuring cylinder = 150cm³
Volume of the metal = 100cm³
Unknown:
Density of the metal = ?
Solution:
Density is the mass per unit volume of a substance;
Density =
Now insert the parameters and solve;
Density = = 12g/cm³
Answer:
P = 17.28*10⁶ N
Explanation:
Given
L = 250 mm = 0.25 m
a = 0.54 m
b = 0.40 m
E = 95 GPa = 95*10⁹ Pa
σmax = 80 MPa = 80*10⁶ Pa
ΔL = 0.12%*L = 0.0012*0.25 m = 3*10⁻⁴ m
We get A as follows:
A = a*b = (0.54 m)*(0.40 m) = 0.216 m²
then, we apply the formula
ΔL = P*L/(A*E) ⇒ P = ΔL*A*E/L
⇒ P = (3*10⁻⁴ m)*(0.216 m²)*(95*10⁹ Pa)/(0.25 m)
⇒ P = 24624000 N = 24.624*10⁶ N
Now we can use the equation
σ = P/A
⇒ σ = (24624000 N)/(0.216 m²) = 114000000 Pa = 114 MPa > 80 MPa
So σ > σmax we use σmax
⇒ P = σmax*A = (80*10⁶ Pa)*(0.216 m²) = 17280000 N = 17.28*10⁶ N
Answer:
True
Explanation:
If the object moves at constant speed then it means that the velocity changes instantaneously although the speed does not change. The change in velocity brings out acceleration and where there is a mass that undergoes acceleration there must be an external resultant force. this force is centripetal force.
By energy conservation we will say
as we know that
also we have
now we will have