Answer:
The correct reaction force in response to Heidi's action force is:
c. The friction is equal to 660 N since the beam is not accelerating.
Explanation:
Heidi's action force does not affect the beam. Since friction resists the sliding or rolling of one solid object over another, there is no friction acting on the beam, in this respect. The reaction force is what makes the dog to move because it acts on it. According to Newton's Third Law of Motion, forces always come in action-reaction pairs. This Third Law states that for every action force, there is an equal and opposite reaction force. This means that the dog exerts some force on Heidi, as he pulls it "forward with a force of 9.55 N."
Answer:
2.5 m
Explanation:
Weight of billboard worker = 800 N
Number of ropes = 2
Length of scaffold = 4 m
Weight of scaffold = 500 N
Tension in rope = 550 N
The sum of the torques will be

The position of the person will be 2.5 m
Answer:
C.As the two objects touch, thermal energy flows as heat from the warmer block to the colder block until particles in both blocks move at the same rate and reach the same temperature.
Explanation:
Heat is the transfer of thermal energy from an object at higher temperature to an object at colder temperature.
The temperature of an object is a measure of how fast the particles in the object move: the higher its temperature, the faster the particles move, the higher the average kinetic energy of the particles in the object. As a result, the particles of the object at higher temperature tend to transfer more energy (called thermal energy) to the particles of the object at colder temperature by colliding with them: this process continues until the particles of the colder object reach the same average kinetic energy as the particles of the warmer object, and this means that the two objects have reached the same temperature.
Yes it does, uh huh. It slows down as it rolls. That's a fact.
In order for the ball to roll forward, it has to push grass out of the way. That takes energy. To bend each blade of grass out of its way, the ball has to use a tiny bit of the kinetic energy that it has, so it gradually runs out of kinetic energy. When its kinetic energy is all gone, it stops moving.