The momentum of each cart is given by:

where
m is the mass of the cart
v is its velocity (at the bottom of the ramp)
To answer the problem, let's calculate the momentum of each of the 4 carts:
1)

2)

3)

4)

Therefore, the cart with greatest momentum is cart 3, so the right answer is
<span>- trial 3, because this trial has a large mass and a large velocity</span>
Answer: option (D)
Explanation:
The potential energy of each of the students is given below as
P.E(student A) = mgh, where m = mass of student A, g is acceleration due to gravity and h = height of the high dive structure.
The mass of student B is twice as much as that of A, hence his mass is 2m and his potential energy is given below as
P.E ( student B) =2mgh = 2(mgh)
Recall that the relationship between potential energy and work done is that
Work done = - (change in potential)
For student A, work done = - mgh
For student B, work done = - 2mgh
From the equations above it can be seen that student B will do twice the work in getting to the high dive structure than student A hence validating option D.
Answer: Because even at high altitudes there is still plenty of oxygen for breathing. However, pressure is what drives the oxygen into the blood stream. At lower pressure we aren't able to breath because the pressure is not high enough to get the O2 into the blood.
Explanation:
Here we know that mass of the person is 90 kg
His weight is given as 30 lbf
so here we can convert it into Newton as we know that
1 lbf = 4.45 N
Now from above conversion

now we can use this to find the gravity at this height



now we know that with height gravity varies as



so above is the height from the surface of earth