Answer:
(a) p = 3.4 kg-m/s (b) 37.78 N.
Explanation:
Mass of a basketball, m = 0.4 kg
Initial velocity of the ball, u = -5.7 m/s (as it comes down so it is negative)
It rebounds upward at a speed of 2.8 m/s (as it rebounds so positive)
(a) Change in momentum = final momentum - initial momentum
p = m(v-u)
p = 0.4 (2.8-(-5.7))
p = 3.4 kg-m/s
(b) Impulse = change in momentum
Ft = 3.4
We have, t = 0.09 s
Hence, this is the required solution.
4.2m/s. Momentum=mass x velocity so 275/65=velocity=4.23
Answer:
Option ( B ) is correct .
Explanation:
To lift a heavy weight , inclined plane is used . Use of inclined plane , makes the task easier because instead of force mg , force mg sinθ is to be used which is less than mg . Here θ is inclination of inclined plane.
If h be the height by which weight is to be lifted
potential energy acquired by weight = mgh
work done by force mg sinθ = mgsinθ x d where d is displacement required .
mg sinθ x d = mgh ( work done by force = potential energy stored in luggage )
d = h / sinθ
d will be more than h
Hence inclined plane increases the distance to be covered by force applied though it decreases the force itself.
Hence option ( B ) is correct .
An isotope of an element contains the same number of protons as the original element however, the number of neutrons depends on the different isotopes of the element.
