Answer:
D. Friction slow down or stop objects in motion.
I have the answer for A. Since there is blockage in the ear canal, some sound waves may not be able to get through or travel as quickly so you would have trouble hearing
<span>It is the lowest velocity which a body must have in order to escape the gravitational attraction of a particular planet or other object.
Every planet has their own corresponding escape velocities. Example - Earth has escape velocity of 11.2 Km/s. It means, if you want to leave the Earth's gravitational field then it's the lowest speed which you need to acquire otherwise you wouldn't do that!
Hope this helps!</span>
Answer = 31.5J (rounded to 1dp)
The question wants to find the work done, where work done can be calculated in the equation:
Work done = Force x Distance
The force is not given in the question, however they give the acceleration and mass, so you can calculate the force using Newton's second law:
Force = Mass x Acceleration
First, calculate the force. The mass is 45kg for the 3 boxes and the acceleration is 12.3m/s^2.
Force = 45 x 12.3
Force = 553.5N
Now that you have the force (553.5N) and distance (57cm), substitute those values into the equation for work done.
Make sure to convert the 57cm into metres (into SI units), otherwise the answer would be wrong.
57cm = 0.057m
Work done = Force x Distance
Work done = 553.5 x 0.057
Work done = 31.5J (rounded to 1dp)
