<u>Answer:</u>
The velocity is 30.279 m/s
<u>Explanation</u>:
Consider the initial speed of the semi-trailer be v
Then, initial kinetic energy = 
According to question, the semi-trailer coast along a ramp, which is inclined at an angle of 170, and to a distance of 160m to stop
Change in vertical position =
= 46.779m
Final potential energy of semitrailer = mgh
Applying principle of conservation of energy,
= mgh
Solving for v, we get 
= 2gh = 2*9.8*46.779 = 916.8684
= 916.8684
v = 30.279 m/s
Therefore, the velocity is 30.279 m/s
Answer: The released electromagnetic wave will travel in +y direction
Explanation:
It should be noted that, in a situation, whereby an excited hydrogen atom releases an electromagnetic wave to return to its normal state. And it's also evident that the futuristic dual electric/magnetic field tester on the electromagnetic wave to find the directions of the electric field and magnetic field is used. Eventually, your device tells you that the electric field is pointing in the positive y direction and the magnetic field is pointing in the positive x direction. Therefore, the released electromagnetic wave will travel in +y direction.
Explanation:
2.
4.
In only the above cases (i.e 1,2,4,5,6,8 ) the object possibly moves at a constant velocity of 
You should have noticed that the sets of forces applied to the object are the same asthe ones in the prevous question. Newton's 1st law (and the 2nd law, too) makes nodistinction between the state of re st and the state of moving at a constant velocity(even a high velocity).
In both cases, the net force applied to the object must equal zero.
Answer:
<h3>0.99 m</h3>
Explanation:
Average velocity is the change of rate of displacement with respect to time;
Average velocity = Displacement/Time
Given
Average velocity of the frog = 1.8m/s
Time = 0.55s
Required
Displacement of the frog
Substitute the given parameters into the formula;
1.8 = displacement/0.55
cross multiply
Displacement = 1.8*0.55
Displacement = 0.99 m
Hence the frog's displacement is 0.99m
Answer:
Mass of bike = 38 kg.
Explanation:
Kinetic energy is given by the expression, 
, where m is the mass and v is the velocity.
Here speed of child riding bike = 6 m/s
Mass of child = 30 kg
Total kinetic energy = 1224 J
Let the mass of bike be, m kg
So, total mass of child and bike = (m + 30) kg
Substituting,
So, mass of bike = 38 kg.
