Answer:
higher is safer
Explanation:
because it is a wet slippery surface, you would need more friction on the tires, to get more traction in the slippery wet road, if you had low friction you would not move anywhere and or could swerve off somewhere
Correct Question:-
A jack exerts a vertical force of 4.5 × 10³
newtons to raise a car 0.25 meter. How much
work is done by the jack?

Given :-



To find:-


Solution:-
we know :-


So:-



























Answer:
h= 46.66 m
Explanation:
Given that
Initial speed of the car ,u = 110 km/h
We know that
1 km/h= 0.277 m/s
u= 30.55 m/s
lets height gain by car is h.
The final speed of the car will be zero at height h.
v²=u²- 2 g h
v= 0 m/s
0²=30.55²- 2 x 10 x h ( g = 10 m/s²)
h= 46.66 m
Answer:
<em>Correct choice: b 4H</em>
Explanation:
<u>Conservation of the mechanical energy</u>
The mechanical energy is the sum of the gravitational potential energy GPE (U) and the kinetic energy KE (K):
E = U + K
The GPE is calculated as:
U = mgh
And the kinetic energy is:

Where:
m = mass of the object
g = gravitational acceleration
h = height of the object
v = speed at which the object moves
When the snowball is dropped from a height H, it has zero speed and therefore zero kinetic energy, thus the mechanical energy is:

When the snowball reaches the ground, the height is zero and the GPE is also zero, thus the mechanical energy is:

Since the energy is conserved, U1=U2
![\displaystyle mgH=\frac{1}{2}mv^2 \qquad\qquad [1]](https://tex.z-dn.net/?f=%5Cdisplaystyle%20mgH%3D%5Cfrac%7B1%7D%7B2%7Dmv%5E2%20%20%20%20%5Cqquad%5Cqquad%20%5B1%5D)
For the speed to be double, we need to drop the snowball from a height H', and:

Operating:
![\displaystyle mgH'=4\frac{1}{2}m(v)^2 \qquad\qquad [2]](https://tex.z-dn.net/?f=%5Cdisplaystyle%20mgH%27%3D4%5Cfrac%7B1%7D%7B2%7Dm%28v%29%5E2%20%5Cqquad%5Cqquad%20%5B2%5D)
Dividing [2] by [1]

Simplifying:

Thus:
H' = 4H
Correct choice: b 4H
You haven't told us what the passing percentage is on the exam,
or what the passing percentage is for the semester, or any of that.