Answer: here are 1,000m in a km, so 200km is 200,000m
200,000m/10m/s = 20,000s
Explanation:
Answer:
25 m/s
Explanation:
Given that:
Initial speed, u = 4 m/s
Final velocity, V = 11 m/s
Time, t = 8 seconds
t2, = 16 seconds
Acceleration, a= (change in velocity) / time interval
a = (11 - 4) / 8
a = 7 / 8 = 0.875m/s²
Final velocity, v2 ;
Acceleration * t2
0.875 * 16 = 14
V2 = 14 m/s
Final speed : v + v2 = (11 + 14)m/s = 25m/s
Answer:
the time needed for her to close the door is 1.36 s.
Explanation:
given information:
Force, F = 220 N
width, r = 1.40 m
weight, W = 790 N
height, h = 3.00 m
angle, θ = 90° = π/2
to find the times needed to close the door we can use the following equation
θ = ω₀t + 1/2 αt²
where
θ = angle
ω = angular velocity
α = angular acceleration
t = time
in this case, the angular velocity is zero. thus,
θ = 1/2 αt²
now, we can find the angular speed by using the torque formula
τ = I α
where
τ = torque
I = Inertia
we know that
τ = F r
and
I = 1/3 mr²
so,
τ = I α
F r = 1/3 mr² α
α = 3 F/mr
= 3 F/(w/g)r
= 3 (220)/(790/9.8) 1.4
= 5.85 rad/s²
θ = 1/2 αt²
π/2 = 1/2 5.85 t²
t = 1.36 s
Answer:
0.0195 m
Explanation:
= density of hockey puck = 9.45 gcm⁻³ = 9450 kgm³
= diameter of hockey puck = 13 cm = 0.13 m
= height of hockey puck = 2.8 cm = 0.028 m
= density of mercury = 13.6 gcm⁻³ = 13600 kgm³
= depth of puck below surface of mercury
According to Archimedes principle, the weight of puck is balanced by the weight of mercury displaced by puck
Weight of mercury displaced = Weight of puck
