The first rule of vectors is that the horizontal and vertical components are separate. Disregarding air resistance, the only thing we have to worry about is gravity.
The appropriate suvat to use for the vertical component is v = u +at
I will take a to be -9.81, you may have to change it to be 10 if your qualification likes g to be 10.
v = 30 + (-9.81x2)
v = 30 - 19.62
=10.38m/s
Therefore we know that after 2.0 s the vertical component will be 10.38ms^-1, ie 10m/s as the answers given are all to 2sf.
The horizontal component is completely separate to the vertical component and since there is no air resistance, it will remain constant throughout the projectiles trajectory. Therefore it will remain at 40ms^-1.
Combining this together we get:
(1) vx=40m/s and vy=10m/s
C. Clear, dry weather. A good way to remember is H for high pressure = H for happy weather; L for low pressure = L for lousy weather (Glad I had someone to tell me this)
Answer:
Explanation:
Given:
- mass of John,
- mass of William,
- length of slide,
(A)
height between John and William, 
<u>Using the equation of motion:</u>
where:
v_J = final velocity of John at the end of the slide
u_J = initial velocity of John at the top of the slide = 0
Now putting respective :
<u>Now using the law of conservation of momentum at the bottom of the slide:</u>
<em>Sum of initial momentum of kids before & after collision must be equal.</em>
where: v = velocity with which they move together after collision
is the velocity with which they leave the slide.
(B)
- frictional force due to mud,
<u>Now we find the force along the slide due to the body weight:</u>
<em><u>Hence the net force along the slide:</u></em>
<em>Now the acceleration of John:</em>
<u>Now the new velocity:</u>
Hence the new velocity is slower by
Use a=(dv/dt) (change in velocity/ change in time)=acceleration
(1.2/5)=acceleration
F=ma (Newton's second law, Force= Mass x Acceleration
=960 x 0.24 F=230.4N If T<230.4N then the tow rope will hold
Answer:
You pull on the oars. By the third law, the oars push back on your hands, but that’s irrelevant to the motion of the boat. The other end of each oar (the blade) pushes against the water. By the third law, the water pushes back on the oars, pushing the boat forward.
