Answer:
Explanation:
340 m/s / 968 cyc/s = 0.3512396... ≈ 35.1 cm
The time taken by the swimmer was 1 hour.
Why?
Since the swimmer is maintaining an angle of 150° while he was swimming, there were two components of the speed (horizontal and vertical). If we want to calculate the time taken by him to cross the river, we need to calculate the vertical speed and consider that the flow's speed is compensated by his horizontal speed.
We can calculate both components of the speed using the following formula:

Now, calculating we have:

Therefore, we have that the horizontal speed is compesating the flow's speed while his vertical speed is used to cross the river which is 1 Km wide.
Hence, we have that the tame taken is:

Have a nice day!
Answer:
a) τ = 0.672 N m
, b) θ = 150 rad
, c) W = 100.8 J
Explanation:
a) for this part let's start by finding angular acceleration, when the angular velocity stops it is zero (w = 0)
w = w₀ + α t
α = -w₀ / t
α = 120 / 2.5
α = 48 rad / s²
The moment of inertia of a cylinder is
I = ½ M R²
Let's calculate the torque
τ = I α
τ = ½ M R² α
τ = ½ 2.8 0.1² 48
τ = 0.672 N m
b) we look for the angle by kinematics
θ = w₀ t + ½ α t2
θ = ½ α t²
θ = ½ 48 2.5²
θ = 150 rad
c) work in angular movement
W = τ θ
W = 0.672 150
W = 100.8 J
Answer:
option C
Explanation:
given,
mass of water = 4 Kg
Water is heated to = 800 W
time of immersion = 10 min
= 10 x 60 = 600 s
using equation of specific heat
Q = m S ΔT
S is the specific heat capacity of water which is equal to 4182 J/kg°C.
and another formula of heat
Q = Pt
now,
P t = m S ΔT
800 x 600 = 4 x 4182 x ΔT
ΔT = 29° C
temperature increased is equal to ΔT = 29° C
Hence, the correct answer is option C