I think D the weight but I’m not sure sorry if I’m wrong
Answer:

Explanation:
Given:
mass, 
time, 
velocity, 
coefficient of kinetic friction between wheels & pavement, 
According to first condition,



According to second condition,
<u>Magnitude of frictional force (which acts opposite to the direction of motion):</u>

where N is the normal reaction.


Now, the impulsive force on the wall if the brakes were applied during the crash:



The energy stored in a capacitor is given by

where C is the value of the capacitance while V is the voltage difference applied to the capacitor.
Let's calculate the energy of the first capacitor:

And now the energy of the second capacitor:

So, the total energy stored in the two capacitors is
Let's assume that ground level is the height 0 meters. The change in potential energy is going to be gravitational potential energy, which is given by PE=mgh.
ΔPE=mgh-mgy
=mg(h-y)
=50(28-0)
=1400 J
Answer:
v'=5.97 m/s
Explanation:
If the friction and fluid friction are ignored, then by law of conservation of mechanical energy, potential energy at the top of the slide must be equal to the kinetic energy at the bottom of the slide. Thus, the height of slide and final speed at the bottom of the slide are related as:

let the final speed be v' when h' = 2 h
