materials with a density less than water will float
Answer:
Permanent magnets can lose their magnetism if they are dropped or banged on enough to bump their domains out of alignment
Explanation:
Answer:
when energy changes from one form to another, it always goes from a more useful to a less useful form. This means that people can't recycle or reuse high quality energy to perform useful work.
Answer:the final speed is 5.01 m/s
Explanation:
Momentum is the product of mass and velocity.
Cart 1 has a mass of 4.2kg and a speed 5.4 m/s
Cart 2 has a mass of 3.2kg and a speed 4.5 m/s
Total momentum before collision is
m1u1 + m2u2. It becomes
4.2×5.4 + 3.2×4.5 = 22.68 + 14.4
= 37.08kgm/s
The carts stick together after colliding head-on. This means that they move with a common velocity, v. Therefore, Total momentum after collision is (m1 + m2)v. It becomes
(4.2 + 3.2)v = 7.4v
According the the law of conservation of momentum, the total momentum before collision = the total momentum after collision. Therefore,
7.4v = 37.08
v = 37.08/7.4 = 5.01 m/s
