Answer:
A. The sound wave will reflect off Buildings and automobiles.
Explanation:
This is because the sound waves would more likely propagate through diffraction through buildings and transmission through the air. It is also more likely to be absorbed by buildings than for multiple reflections to occur off buildings and automobiles. In the process of reflection, these materials would absorb the sound energy thereby reducing its ability to reflect.
Answer:
D. a person pulling a sled.
Explanation:
contact force only occurs when something directly comes in contact with another object.
a. is wrong because that is called magnetic force.
b. gravitational force
c. is an electrical force
Answer:
Explanation:
Given:
- mass of vehicle,
- radius of curvature,
- coefficient of friction,
<u>During the turn to prevent the skidding of the vehicle its centripetal force must be equal to the opposite balancing frictional force:</u>
where:
coefficient of friction
normal reaction force due to weight of the car
velocity of the car
is the maximum velocity at which the vehicle can turn without skidding.
Here’s my work to your question. I used Newton’s Second Law and a kinematics equation to arrive at the answer.