Answer:
400 N
Explanation:
By the law of friction,
is the maximum frictional force, 
is the coefficient of friction and 
is the reaction on the refrigerator. On a horizontal surface, the reaction is equal to the weight of the refrigerator.
While not moving, the fricition on the refrigerator is static friction. So, 
This is the maximum frictional force and is more than the applied horizontal force of 400 N. Frictional force cannot be more than the applied force, else it would actually pull the refrigerator backwards (a strange thing, if it were to happen). It is equal to the extent of the applied force because the applied force is not enough to overcome the maximum.
Hence the frictional force is 400 N.
PS: Note that we do not use the coefficient of kinetic friction because applied force could not overcome the static friction.
Answer:
Perpendicular to the surface
Explanation:
- Electric field lines represent the direction of the electric field. The electric field lines also correspond to the direction along which the gradient of the electric potential is maximum.
- Equipotentials are lines or surfaces along which the electric potential is constant: the electric potential does not change moving along an equipotential surface.
Given the two definitions, equipotential lines are always perpendicular to the electric field lines. Therefore, in this problem, the direction of the electric field is perpendicular to the spherical equipotential surface.
<h3><u>Answer and explanation;</u></h3>
- <u>Melting point</u> is defined as the temperature at which solid and liquid phases are in equilibrium. It is the temperature at which a solid changes state from solid to liquid at atmospheric pressure.
- <u>Boiling poin</u>t is the temperature at which the vapour pressure of a liquid is equal to the external pressure. It is the temperature at which a substance changes from a liquid into a gas.
- <u>The flash point </u>of a flammable liquid or volatile liquid is the lowest temperature at which it can form an ignitable mixture in air. At this temperature the vapor may cease to burn when the source of ignition is removed.
Answer:
If one plays ice hockey he should must have necessary equipment to support his sport. These equipment include Ice Skates,Helmet with Cage and Mouth-guard:, Hockey stick, Hockey pants,Hockey gloves, shoulder pads, elbow pads, Shin Guard:Neck guard and Jockstrap (men) or Pelvic protector (women)
Explanation:
Explanation:
A) Use Hooke's law to find the spring constant.
F = kx
40 N = k (0.4 m)
k = 100 N/m
B) Period of a spring-mass system is:
T = 2π √(m / k)
T = 2π √(2.6 kg / 100 N/m)
T = 1 s
Frequency is the inverse of period.
f = 1 / T
f = 1 Hz
