Answer:
Explanation:18kt alloy contains
i) 75% of gold
rhogold=19.3g/cm^3
=75/100×19.3
=14.475g/cm^3
ii) 16% of silver
rhosilver=10.5g/cm^3
=16/100×10.5
=1.68g/cm^3
iii) 9% of copper
rhocopper =8.90g/cm^3
=9/100×8.9
=0.801g/cm^3
Overall density of 18kt gold
=(0.801+1.68+14.475)g/cm^3
=16.956g/cm^3
=17g/cm^3 to 3s.f
Answer: 1.d) The acceleration of an object is always less than the acceleration due to gravity, g (9.81m/s^-2)
2.a)acceleration decreases
Explanation:
Newton's second law:
Newton's second law states that the acceleration of an object is defined by two variables which is the total force acting on the object and the mass of that object. The acceleration is directly proportional to the net force that is applied on an object and inversely proportional to the mass of that object.
When the force applied on an object is increased so does the acceleration of an object however if the mass increase the acceleration decreases.
This can be felt when you look at the truck which usually carry heavy loads they seem to drive slow due to the load hence their acceleration is decreased by the mass that these truck carry .
Answer:
A is a gas becasue it contracts and the containers change.
Answer:
humans and whales are both mammals
humans and whales can breathe air
