They send out waves differently and cannot be heard easily
Answer:
D) momentum of cannon + momentum of projectile= 0
Explanation:
The law of conservation of momentum states that the total momentum of an isolated system is constant.
In this case, the system cannon+projectile can be considered as isolated, because no external forces act on it (in fact, the surface is frictionless, so there is no friction acting on the cannon). Therefore, the total momentum of the two objects (cannon+projectile) must be equal before and after the firing:

But the initial momentum is zero, because at the beginning both the cannon and the projectile are at rest:

So the final momentum, which is sum of the momentum of the cannon and of the projectile, must also be zero:

80/60=
1.3333...........................................
Answer:
No
Explanation:
Electric potential is the work done to bring a unit of charge (1 C) from infinity to a point inside an electric field.
Electric potential energy of a charge q is the energy required to keep it in an electric potential V. Electric potential energy is given by,
U = qV
Hence even if the two charges are on an equipotential surface (surface where the potential is the same at all points), the potenial energy will be different if the magnitude or nature of the charges are different.
The correct answer is option (c) i.e. one
<span>The seat belt across your chest should have about one fist width of the slack. Because the seat belt across your chest is required to have minimum fist width of the slack to hold the body in place and to avoid slamming of the body against the seat belt in case of a collision at high speeds. To have one fist width of the slack, makes it a safest to wear it in case of any collision. </span>