Answer:
-8.4°C
Explanation:
From the principle of heat capacity.
The heat sustain by an object is given as;
H = m× c× (T2-T1)
Where H is heat transferred
m is mass of substance
T2-T1 is the temperature change from starting to final temperature T2.
c- is the specific heat capacity of ice .
Note : specific heat capacity is an intrinsic capacity of a substance which is the energy substained on a unit mass of a substance on a unit temperature change.
Hence ; 35= 1× c× ( T2-(-25))
35= c× ( T2+25)
35 =2.108×( T2+25)
( T2+25)= 35/2.108= 16.60°{ approximated to 2 decimal place}
T2= 16.60-25= -8.40°C
C, specific heat capacity of ice is =2.108 kJ/kgK{you can google that}
The boy's momentum is 160 kg*m/s north.
The formula of momentum is p = mv, where p is momentum.
p = 40 kg * 4m/s north
p =160 kg*m/s north<span>Thank you for posting your question. I hope you found what you were after. Please feel free to ask me more.</span>
Answer:
the shooting angle ia 18.4º
Explanation:
For resolution of this exercise we use projectile launch expressions, let's see the scope
R = Vo² sin (2θ) / g
sin 2θ = g R / Vo²
sin 2θ = 9.8 75/35²
2θ = sin⁻¹ (0.6)
θ = 18.4º
To know how for the arrow the tree branch we calculate the height of the arrow at this point
X2 = 75/2 = 37.5 m
We calculate the time to reach this point since the speed is constant on the X axis
X = Vox t
t2 = X2 / Vox = X2 / (Vo cosθ)
t2 = 37.5 / (35 cos 18.4)
t2 = 1.13 s
With this time we calculate the height at this point
Y = Voy t - ½ g t²
Y = 35 sin 18.4 1.13 - ½ 9.8 1,13²
Y = 6.23 m
With the height of the branch is 3.5 m and the arrow passes to 6.23, it passes over the branch