Answer:
a) (95.4 i^ + 282.6 j^) N
, b) 298.27 N 71.3º and c) F' = 298.27 N θ = 251.4º
Explanation:
a) Let's use trigonometry to break down Jennifer's strength
sin θ = Fjy / Fj
cos θ = Fjx / Fj
Analyze the angle is 32º east of the north measuring from the positive side of the x-axis would be
T = 90 -32 = 58º
Fjy = Fj sin 58
Fjx = FJ cos 58
Fjx = 180 cos 58 = 95.4 N
Fjy = 180 sin 58 = 152.6 N
Andrea's force is
Fa = 130.0 j ^
We perform the summary of force on each axis
X axis
Fx = Fjx
Fx = 95.4 N
Axis y
Fy = Fjy + Fa
Fy = 152.6 + 130
Fy = 282.6 N
F = (95.4 i ^ + 282.6 j ^) N
b) Let's use the Pythagorean theorem and trigonometry
F² = Fx² + Fy²
F = √ (95.4² + 282.6²)
F = √ (88963)
F = 298.27 N
tan θ = Fy / Fx
θ = tan-1 (282.6 / 95.4)
θ = tan-1 (2,962)
θ = 71.3º
c) To avoid the movement they must apply a force of equal magnitude, but opposite direction
F' = 298.27 N
θ' = 180 + 71.3
θ = 251.4º
The heat required to convert the unknown substance X from one phase to another is 1600 J times the specific heat of that substance.
Explanation:
The heat energy required to convert a substance or to heat up or increase the temperature of a substance can be obtained from the specific heat formula.
As per this formula, the heat energy applied should be equal to the product of mass of the substance with temperature gradient and also with specific heat of the substance. Basically, the heat provided to increase or convert a substance should be more than the specific heat of the substance.

Since, here the mass of the substance X is given as m = 20g and the temperature change is given from -10°C to 70°C.
Then ΔT = (70-(-10))=70+10=80°C.
As the substance is unknown, the specific heat of that substance can also not be determined. Hence keep it as C.

Q = 1600C J
Thus, the heat required to convert the unknown substance X from one phase to another is 1600 J times the specific heat of that substance.
Answer:
(A) Q = 2.26×10⁶J
(B) ΔT = 9°C
(C)
Explanation:
We have been given the mass of the hiker, the volume of water from which we can calculate the mass knowing that the density if water is 1000kg/m³.
Evaporation is a phase change and occurs at a constant temperature. We would use the latent heat of vaporization to calculate the amount of heat evaporated.
We would then equate this to the heat change it brings about in the hiker's body and then calculate the temperature drop.
See the attachment below for full solution.
Answer:
Part a)

Part b)

Part c)

Explanation:
Part a)
As we know that the velocity of the tip of the kicker's shoe is given as

also the length of the tip of the shoe from his hip joint is given as

now the angular speed is given as



Part b)
As we know that force on the ball is given as rate of change in momentum of the ball
so it is given as

so we have



Part c)
As we know that the formula of range is given as

now for maximum range we know




Answer:
the net force is 101587.5 N
Explanation:
The speed of wind
v = 30 m/s
The area of roof,
A = 175 m 2
The expression for the Bernoulli's theorem.
P = 12 ρv 2 ...... (1)
Here,
P is the pressure difference,
ρ is the density of air and
v is the speed of wind.
The expression for the pressure.
P = F A ..... (2)
Here,
F is the force and
A is the area of roof.
Part (a)
Substitute the values for the pressure difference in equation (1)
P = 12 × 1.29 × (30) 2 P = 580.5 Pa
Thus, the pressure difference at the roof between the inside and outside air is
580.5 Pa
Part (b)
Substitute the values for the net force in equation (2)
580.5 = F 175 F = 101587.5 N
Thus, the net force is 101587.5 N.