Answer:
0.182 m/s
Explanation:
m1 = 30,000 kg, m2 = 110,000 kg, u1 = 0.85 m/s
let the velocity of loaded freight car is v
Use the conservation of momentum
m1 x u1 + m2 x 0 = (m1 + m2) x v
30,000 x 0.85 = (30,000 + 110,000) x v
v = 0.182 m/s
Answer:
They both describe atoms as being made up of positive and negative matter.
Explanation:
In both Bohr's model and Thomson model, the atom consists of positively-charged matter and negatively-charged matter. However, the structure of the atom in the two models is totally different:
- in Thomson's model, the atom consists of a large sphere of uniform positive charge, and electrons (which are negatively charged) are scattered all around inside this sphere
- In Bohr's model, the atom consists of a small, positively charged nucleus, while the electrons (negatively charged) orbit around the nucleus in precise orbits.
If everything else is held constant ... the substance from which
the conductor is formed, its cross-sectional area, its temperature
everywhere along its length ... then yes, its resistance will be
directly proportional to its length.
consider the velocity towards the pitcher as positive
m = mass of the baseball = 0.145 kg
v₀ = initial velocity of the baseball = - 39 m/s
v = final velocity of the baseball = 52 m/s
t = time of contact = 3 x 10⁻³ sec
F = average force between bat and ball
Using impulse-change in momentum equation
F t = m (v - v₀ )
F (3 x 10⁻³) = (0.145) (52 - (- 39))
F = 4398.33 N
Answer:
The correct option is that (She decreases her moment of inertia, thereby increasing her angular speed.)
Explanation:
When an object is in circular motion, the vector that describes it is known as angular momentum. Angular momentum is conserved or constant when an object is spinning in a closed system and no external torques are applied to it. An example of conservation of angular momentum is seen when a woman is sitting on a spinning piano stool with her arms extended. Her angular momentum is conserved because the net torque on her is negligibly small as the friction is exerted very close to the pivot point.
When she folds her arms,her rate of spin increases greatly decreasing her moment of inertia. The work she does to pull in her arms results in an increase in rotational kinetic energy( that is, increase in her angular speed). I hope this helps, thanks!
