Answer:
114.19186 m
Explanation:
v = Velocity of girl at bottom = 7.1 m/s
= Coefficient of kinetic friction = 0.045
g = Acceleration due to gravity = 9.81 m/s²
d = Distance
N = Normal force = 783 N
The weight of the sled and girl is considered as the sum of the frictional force and weight
Hence we use the following equation where the kinetic energy and potential energy are conserved

The sled travels 114.19186 m on the level ground before coming to a rest
Answer:
the velocity of the water flow is 7.92 m/s
Explanation:
The computation of the velocity of the water flow is as follows
Here we use the Bernouli equation
As we know that

= 7.92 m/s
Hence, the velocity of the water flow is 7.92 m/s
We simply applied the above formula so that the correct value could come
And, the same is to be considered
Answer:
1.53 s
Explanation:
Initially vertical component of velocity of the ball, uy = 7.5 m/s
Net displacement is vertical direction is zero, Δy =0
Use second equation of motion:
Δy = uy t + 0.5 a t²
Here, acceleration a = -g (g =9.8 m/s²)
Substitute all the values and solve for g
0 = 7.5 t -0.5 (9.8)t²
7.5 t = 4.9 t²
t = 1.53 s
I think there is 19 protons
D=m/v
m=67.2 g
v=2^3=8 cm3
d=67.2/8
d=8.4 g/cm3