Answer:
h = 22.35 m
Explanation:
given,
initial speed of the rock,u = 0 m/s
length of the window,l = 2.7 m
time taken to cross the window,t = 0.129 s
Speed of the rock when it crosses the window
v = 20.93 m/s
height of the building above the window
using equation of motion
v² = u² + 2 g h
20.93² = 0² + 2 x 9.8 x h
h = 22.35 m
Hence, the height of the building above the top of window is equal to h = 22.35 m
Answer:
A horse is running at 12m/s accelerated to 38m/s in 10 seconds. What is the horses acceleration.
2.6m/s^2
I think it’s C. Stroke if not then D
Answer:
a = 1 m/s² and
Explanation:
The first two parts can be seen in attachment
We use Newton's second law on each axis
Y axis
Ty - W = 0
Ty = w
X axis
Tx = m a
With trigonometry we find the components of tension
Sin θ = Ty / T
Ty = T sin θ
Cos θ = Tx / T
Tx = T cos θ
We calculate the acceleration with kinematics
Vf = Vo + a t
a = (Vf -Vo) / t
a = (20 -10) / 10
a = 1 m/s²
We substitute in Newton's equations
T Sin θ = mg
T cos θ = ma
We divide the two equations
Tan θ = g / a
θ = tan⁻¹ (g / a)
θ = tan⁻¹ (9.8 / 1)
θ = 84º
We see that in the expression of the angle the mass does not appear therefore you should not change the angle