Answer: (1, 30), (2,10), (3,40), (4,20)
Explanation:
B. Asteroids have a nearly circular orbit.
Answer:
(a) They must have same direction
(b) It is not necessary for them to have same magnitudes
Explanation:
(a)
Momentum is a vector quantity. It is the product of mass (scalar) and velocity (vector). Thus, if the direction of velocity is changed, then as a result the direction of momentum will also change or its magnitude or component in the same direction will change. Hence, for the two objects to have same momentum, the directions of their velocities must also be the same.
(b)
Since, the momentum is product of velocity and mass. It is possible that two bodies of different masses with different velocities might have same momentum, provided the direction of their velocities is same.
For example, take a body of mass 4 kg moving with speed 5 m/s. It will have a momentum of 20 N.s. Now, consider another body of mass 2 kg, moving with speed 10 m/s. It will also have a momentum of 20 N.s.
Thus, it is not necessary for two objects to have same magnitude of velocity to have same momentum.
Answer:
Work = 6912 joules
Explanation:
Non-conservative forces are dissipative forces such as friction or air resistance. These forces take energy away from the system as the system progresses, energy that you can't get back. These forces are path dependent; therefore it matters where the object starts and stops.
Total mass = 40 + 8 = 48kg
Initial speed u= 6 m/s
Final speed v = 3*initial
Final speed v = 3* 6 = 18 m/s
Distance s = 15
Acceleration a is?
V² = U² + 2aS
18² = 6² + 2a*15
324 = 36 + 30a
324-36= 30a
288 = 30a
288/30 = a
9.6= a
Force = mass* acceleration
Force = 48*9.6
Force = 460.8N
Work = force*distance
Work = 460.8*15
Work = 6912 joules
