Some examples of when friction is helpful are: to help the movement of tires. When you walk, and also, when you erase. :)
Answer:
887.1Hz
Explanation:
Given parameters:
Speed of sound wave = 330m/s
Wavelength = 0.372m
Unknown:
Frequency = ?
Solution:
To solve this problem, we use the expression below:
Speed = Frequency x wavelength
330 = Frequency x 0.372
Frequency = 887.1Hz
Answer:
The value of radiation pressure is 
Pa
Explanation:
Given:
Intensity 
Area of piece 
From the formula of radiation pressure in terms of intensity,
Where 
radiation pressure, 
speed of light
We know value of speed of light,
Put all values in above equation,
Pa
Therefore, the value of radiation pressure is Pa
Answer:
<em>The force of friction acting on the block has a magnitude of 15 N and acts opposite to the applied force.</em>
Explanation:
<u>Net Force
</u>
The Second Newton's law states that an object acquires acceleration when an unbalanced net force is applied to it.
The acceleration is proportional to the net force and inversely proportional to the mass of the object.
If the object has zero net force, it won't get accelerated and its velocity will remain constant.
The m=2 kg block is being pulled across a horizontal surface by a force of F=15 N and we are told the block moves at a constant velocity. This means the acceleration is zero and therefore the net force is also zero.
Since there is an external force applied to the box, it must have been balanced by the force of friction, thus the force of friction has the same magnitude acting opposite to the applied force.
The force of friction acting on the block has a magnitude of 15 N opposite to the applied force.
Answer:
d. decreases
Explanation:
The law of conservation of momentum tells us that the sum of momenta before the collision is equal to the sum of momenta after the collision. The bag has no momentum as it falls onto the boat because its velocity is zero in the horizontal direction. But after it hits the boat, it's momentum increases while the momentum of the system remains the same. That means a component of the system must decrease somewhere else. And that component is the velocity, not the mass, of the boat.
