-- During the time the ball is flying from the high roof to the low roof,
it's going to fall (100-25) = 75 meters.
How long does it take an object dropped from rest to fall 75 meters ?
Distance = (1/2) · (gravity) · (time)²
75 m = (4.9 m/s²) · (time)²
Time² = (75 m) / (4.9 m/s²)
Time² = 15.31 sec²
Time = √(15.31 sec²) = 3.91 seconds
So the ball has to cover the horizontal distance of 20 meters
in 3.91 seconds.
Distance = (speed) · (time)
20 m = (speed) · (3.91 sec)
Speed = (20 m) / (3.91 sec)
Speed = 5.11 m/s
When they meet the 40-kg boy would have moved a distance of 6 m.
<h3>Distance moved by the 40 kg boy</h3>
Apply the principle of center mass;
Take the 40 kg mass as the reference point;
X(40 kg) = (40kg x 0 + 60kg x 10 m)/(40 kg + 60 kg)
X(40 kg) = (600)/(100)
X(40 kg) = 6 m
Thus, when they meet the 40-kg boy would have moved a distance of 6 m.
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Answer:
s=62.5m
Explanation:
Use the equation v²=u²+2as, where v is the final velocity, u is the initial velocity, a is the acceleration and s is the distance.
0²=25²+2(-5)s
10s=625
s=62.5m
Answer:
a) w = 25.1 rad/s, b) θ = 0.9599 rad
, c) α = 328.1 rad/s² d) t= 0.0765 s
Explanation: Let's work on this exercise with the equations of angular kinematics
a) The angular velocity is
w = 4.00 rev / s (2π rad / 1 rev)
w = 25.1 rad/s
b) let's reduce the angle of degrees to radians
θ = 55 ° (π rad / 180 °)
θ = 0.9599 rad
c) Let's use the initial angular velocity as the system part of the rest is zero
w² = w₀² + 2 α θ
α = w² / 2 θ
α = 25.1²/2 0.9599
α = 328.1 rad / s²
d)
w = w₀ + α t
t = w / α
t = 25.1 / 328.1
t= 0.0765 s
Answer:
A.They alternately compress and pull apart the particles in matter.
B. They are the first waves detected after an earthquake.
Explanation:
P-waves, also known as a compressional wave is the wave that shakes the ground in the same and opposite direction of the wave i.e. back and forthe motion of the ground. They compress and pull apart the material alternatively. The disturbances due to these waves have small magnitude thus making them non destructive. These waves travel at faster speed as compared to other seismic waves and thus help in detecting the earthquake. These wave can travel through liquid, solid and gases.