Answer:
a) 70 N, b) b. Each initially applied a force bigger than static friction to get the box moving and accelerating, then when the desired final speed was achieved they reduced the force to make the net force zero.
Explanation:
a) A constant speed means that magnitude of friction force is equal to the magnitude of the external force. The friction force is directly proportional to the normal force, which is equal to the weight of the box. Therefore, the magnitude of the force is 70 N.
b) Alice used initially a greater force to accelerate the box up to needed speed and later reduced the external force to keep speed constant. The right choice is option b.
Energy of motion is the literal definition of kinetic energy
Answer:
Explanation:
To calculate the momentum of a moving object multiply the mass of the object times its velocity. The symbol for momentum is a small p. So, the momentum of the object is calculated to be 8.0 kg-m/s. Note the unit for momentum.
Speed = wavelength x frequency determine the speed of a wave,
Answer:
C
Explanation:
Gravitational forces are acting on a masses . It gives
F = (GmM)/ r2
F - force acting on two masses
G - Gravitational Constant
m, M - Mass
r - distance between two mass
Magnetic force acting on due to magnetic fields
Nuclear force is acting on due to nuclear reaction . This is happened inside th sun between H and He
Elastic force is acting due to stress and strain of the object
