Answer:
(a i - 2a j) / 2
Explanation:
a1 = a i
a2 = a j
a3 = - (i + j) (2a) = - 2a i - 2a j
a4 = (i - j) (3a) = 3a i - 3a j
Let the mass of each particle is m.
Use the formula of acceleration of centre of mass
a cm = (m1 a1 + m2 a2 + m3 a3 + m4 a4) / (m1 + m2 + m3 + m4)
a cm = (a i + aj - 2a i - 2a j + 3a i - 3a j) / 4
a cm = ( 2a i - 4a j) / 4
a cm = (a i - 2a j) / 2
Answer:
The value of the centripetal forces are same.
Explanation:
Given:
The masses of the cars are same. The radii of the banked paths are same. The weight of an object on the moon is about one sixth of its weight on earth.
The expression for centripetal force is given by,
where, is the mass of the object, is the velocity of the object and is the radius of the path.
The value of the centripetal force depends on the mass of the object, not on its weight.
As both on moon and earth the velocity of the cars and the radii of the paths are same, so the centripetal forces are the same.
Momentum = mass * velocity
So C
Answer:
Compound.
Explanation:
A compound is a substance formed when two or more elements are chemically joined. Water, salt, and sugar are examples of compounds. When the elements are joined, the atoms lose their individual properties and have different properties from the elements they are composed of.
Answer:
300 cos 30 = 40 a + 40 * .2 * 10
Total force = mass * acceleration + frictional force
260 = 40 a + 80
a = 180 / 40 = 4.5 m/s^2
Check:
15 a + 15 * 10 * .2 = T acceleration of 15 kg block (assuming a = 4.5)
T = 15 (4.5) + 30 = 97.5 force required to accelerate 15 kg block
260 - 97.5 = 162.5 net force on 25 kg block
162.5 = 4.5 (25) + 25 * 10 * .2
162.5 = 112.5 + 50 = 162.5
4.5 m/s^2 checks out as correct