Answer:
vf = 12.51 m/s
Explanation:
Newton's second law to the grocery cart:
∑F = m*a Formula (1)
∑F : algebraic sum of the forces in Newton (N)
m : mass s (kg)
a : acceleration (m/s²)
We define the x-axis in the direction parallel to the movement of the grocery cart and the y-axis in the direction perpendicular to it.
Forces acting on the grocery cart
W: Weight of the block : In vertical direction downward
N : Normal force : In vertical direction upward
F : horizontal force
Calculated of the mas of the grocery cart (m)
W = m*g
m = W/g
W = 94.0 N , g = 9.81 m/s²
m = 94/9.81
m = 9.58 Kg
Calculated of the acceleration of the grocery cart (a)
∑F = m*a
F = m*a
42.6 = (9.58)*a
a = (42.6) / (9.58)
a = 4.45 m/s²
Kinematics Equation of the grocery cart
Because the grocery cart moves with uniformly accelerated movement we apply the following formula to calculate its final speed :
vf²=v₀²+2*a*d Formula (2)
Where:
d:displacement (m)
v₀: initial speed (m/s)
vf: final speed (m/s)
a: acceleration (m/s²)
Data:
v₀ = 0
a = 4.45 m/s²
d = 17.6 m
We replace data in the formula (2) :
vf²=v₀²+2*a*d
vf² = 0+2*(4.45)*(17.6)
vf² = 156.64

vf = 12.51 m/s
Answer:
W= 4.4 J
Explanation
Elastic potential energy theory
If we have a spring of constant K to which a force F that produces a Δx deformation is applied, we apply Hooke's law:
F=K*x Formula (1): The force F applied to the spring is proportional to the deformation x of the spring.
As the force is variable to calculate the work we define an average force
Formula (2)
Ff: final force
Fi: initial force
The work done on the spring is :
W = Fa*Δx
Fa : average force
Δx : displacement
:Formula (3)
: final deformation
:initial deformation
Problem development
We calculate Ff and Fi , applying formula (1) :


We calculate average force applying formula (2):

We calculate the work done on the spring applying formula (3) : :
W= 11N*(0.7m-0.3m) = 11N*0.4m=4.4 N*m = 4.4 Joule = 4.4 J
Work done in stages
Work is the change of elastic potential energy (ΔEp)
W=ΔEp
ΔEp= Epf-Epi
Epf= final potential energy
Epi=initial potential energy




W=ΔEp= 5.39 J-0.99 J = 4.4J
:
Given:
m = 555 g, the mass of water in the calorimeter
ΔT = 39.5 - 20.5 = 19 °C, temperature change
c = 4.18 J/(°C-g), specific heat of water
Assume that all generated heat goes into heating the water.
Then the energy released is
Q = mcΔT
= (555 g)*(4.18 J/(°C-g)*(19 °C)
= 44,078.1 J
= 44,100 J (approximately)
Answer: 44,100 J
Answer:
(c) 4M
Explanation:
The system is a loaded spring. The period of a loaded spring is given by

<em>m</em> is the mass and <em>k</em> is the spring constant.
It follows that, since <em>k</em> is constant,

where <em>C</em> represents a constant.


When the period is doubled,
.

Hence, the mass is replaced by 4M.
Current is split among different branches of wires, or voltage is equal throughout?