a is the correct answer
Explanation:
no.of proton defines atomic number in an atom
Answer: liquid to solid
Explanation: Kinetic energy is the energy possessed by an object by virtue of its motion.
Solid is the phase of matter where particles have strongest inter molecular forces and thus molecules posses no kinetic energy.
Liquid is the phase of matter where kinetic energy of the molecules is almost equal to the inter molecular forces.
Gas is the phase of matter where kinetic energy of the molecules is more than the inter molecular forces present among molecules and hence the molecules move randomly.
Thus the phase change is from liquid to solid.
Answer:
640 N
Explanation:
Given :
Mass of horse, m = 40kg
initial speed of horse, u = 8 m/s
final speed of horse, v = 0 m/s (because horse comes to a sudden stop)
time taken to stop, t = 0.5 s
recall that acceleration = change in speed / time taken for the change
or
a = (v - u) / t (substituting the above values)
a = (0 - 8) / 0.5
a = -16 m/s² (i.e it is a deceleration of 16 m/s²)
since we are not concerned about the direction of the force, we can simply use the absolute value of acceleration which is a = 16 m/s²
also recall that
Force = mass x acceleration
F = ma (substituting the values above)
F = 40kg x 16 m/s
F = 640 N
The net force is the total force. Add 4 and 2 together and you get 6. Since 5 N are pushing against it, you subtract that from 6. The net force is 1 N.
