I believe it is henry Moseley he designed it in 1900
Answer:
2.42 seconds
Explanation:
Assume that air resistance is negligible, use trigonometry to find the vertical component of the velocity by using trigonometry:
<span>31⋅<span>sin50</span>=23.7</span>
Where 31 <span>m<span>s<span>−1</span></span></span> is the hypotenuse and by using sin to get the opposite component (vertical velocity) of the trajectory.
Now comes the use of the formula:
v = u + at
where v is the final velocity (0 <span>m<span>s<span>−1</span></span></span>), u is the initial velocity (31 <span>m<span>s<span>−1</span></span></span> ), a is the acceleration of gravity (9.81 <span>m<span>s<span>−2</span></span></span>) and t is the time it takes to arrive at the top of the trajectory.
By making t as the subject:
<span>t=<span><span>v−u</span>a</span></span>
You can calculate the value of t:
<span><span><span>0−23.7</span><span>−9.81</span></span>=2.42</span> (to 3 significant figures)
Better way to see it:
<span><span><span>0−<span>(31⋅<span>sin50</span>)</span></span><span>−9.81</span></span>=2.421</span> (to 4 significant figures)
Note: You must remember that you are dealing with velocity, not speed . Since velocity is a vector quantity, you must select the direction at which values will be positive. In my example, I set my upward direction as the positive value while my downward vectors as negative value (a, acceleration, 9.81 <span>m<span>s<span>−1</span></span></span>).
Answer:
False
Explanation:
It is not necessary, that when the initial speed of the object is zero then it must be at origin.
It may be the object starts motion from the left of origin.
Most likely answer would be A
Answer:
Well I'll say the answer is
A.21
B.21
Explanation:
The law of conservation of momentum states that the total momentum in a system remains constant
And
To find the Total momentum in a body, you'll have to multiply the mass of the body to it's velocity
And
To find the total momentum, you'll add the momenta in every body present in the system