The answer is refraction. When a wave from one medium enters another medium, its direction changes due to the change of speed (phase velocity changes but frequency remains the same). The wave slows down when it enters a denser medium from the one it came from hence its path seems to bend.
Answer:
530.43m/s
Explanation:
Given data
Mass m = 0.23kg
PE= 61J
From the expression for potential energy
PE= mgh
after it was shot
PE=KE
KE= 1/2mv^2
So
PE= 1/2mv^2
substitute
61= 1/2*0.23*v^2
61=0.5*0.23*v^2
61=0.115v^2
divide both sides by 0.115
v= 61/0.115
v=530.43 m/s
Hence the velocity is 530.43m/s
D it’s definitely D if I’m wrong sorry…
Answer:
Option (b) is correct.
Explanation:
Elastic collision is defined as a collision where the kinetic energy of the system remains same. Both linear momentum and kinetic energy are conserved in case of an elastic collision.
Inelastic collision is defined as a collision where kinetic energy of the system is not conserved whereas the linear momentum is conserved. This loss of kinetic energy may due to the conversion to thermal energy or sound energy or may be due to the deformation of the materials colliding with each other.
As given in the problem, before the collision, total momentum of the system is and the kinetic energy is . After the collision, the total momentum of the system is , but the kinetic energy is reduced to . So some amount of kinetic energy is lost during the collision.
Therefor the situation describes an inelastic collision (and it could NOT be elastic).
Answer:
B
Explanation:
From Newton's law of motion, we have:
V^2 = U^2 + 2gH
Where V and U are final and initial velocity respectively.
H is the height.
For the object to have a sustain a maximum height it means the final velocity of the object is zero.
By computing the height of the object sustain by A, we have:
0^2 = 2^2 -2×10×H
0= 4 -20H
4 = 20H;
H= 0.2m
For object B we have;
0^2 = 1^2 -2×10×H
0 = 1 -20H
H = 1/20= 0.05m
From computing the height sustain by both objects, we see object B is projected at a shorter height into atmosphere than A.
Hence object B will return to the ground first.