The acceleration of the object after 3 seconds of fall is -9.8 m/s².
The given parameters;
- initial velocity of the object, u = 0
- time of motion of the object, t = 3 seconds
Acceleration is the change in velocity per change in time of motion.
The acceleration of the object after 3 seconds of fall is calculated as follows;
- Since the object is in free fall, the object experiences only acceleration due to gravity.
- the magnitude of this acceleration due to gravity is 9.8 m/s²
- the direction of this acceleration is downwards
Thus, the acceleration of the object after 3 seconds of fall is -9.8 m/s².
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Answer:
Explanation:
Given
mass of cylinder is M
radius R
velocity of center of mass is v
As there is no slipping therefore cylinder will rotate as well as translate
Moment of inertia of cylinder 
Kinetic Energy of cylinder 
Rotational energy 
for rolling

where 

Total kinetic Energy 
Answer:
Make sure everything is organized have a planner it can help
Get rid of all distractions
Listen to music if it helps you concentrate
Have your notes
Being willing to stay focus on what you are doing
Understand what you are doing
And most off all Be Happy and Remain Calm : )
Explanation:
Draw a free body diagram for each disc.
Disc A has three forces acting on it: 86.5 N up, T₁ down, and Wa down.
∑F = ma
86.5 N − T₁ − Wa = 0
Wa = 86.5 N − T₁
ma × 9.8 m/s² = 86.5 N − 55.6 N
ma = 3.2 kg
Disc B has three forces acting on it: T₁ up, T₂ down, and Wb down.
∑F = ma
T₁ − T₂ − Wb = 0
Wb = T₁ − T₂
mb × 9.8 m/s² = 55.6 N − 36.5 N
mb = 1.9 kg
Disc C has three forces acting on it: T₂ up, T₃ down, and Wc down.
∑F = ma
T₂ − T₃ − Wc = 0
Wc = T₂ − T₃
mc × 9.8 m/s² = 36.5 N − 9.6 N
mc = 2.7 kg
Disc D has two forces acting on it: T₃ up and Wd down.
∑F = ma
T₃ − Wd = 0
Wd = T₃
md × 9.8 m/s² = 9.6 N
md = 0.98 kg
Answer: A.
Explanation: Roughly 180 - 200 million years ago, just before the first dinosaurs evolved. Mammals themselves evolved from a group or reptiles which exhibited mammal-like traits. One of them was specialized teeth. Reptiles tend to have teeth all the same shape. The mammal-like reptiles evolved tiny teeth in front of the jaw and two pairs of over sized fangs along the the sides. Like modern mammals, the head was large in proportion to the rest of the body. The jaws were also evolving another mammal trait, the ability to move sideways. Despite the lack of specialized teeth, acute hearing and the ability to chew, the dinosaurs evolved an adaptation which made them far more successful than mammals--modified leg bones. These limbs could be articulated directly under their bodies. This enabled the legs to support more weight, since the limbs were now under the body instead of at the sides. Then dinosaurs did something which secured their dominance for the next 120 million years - they began to stand on two legs. Although the back was still parallel to the ground, running on two legs greatly increased the dinosaur's speed. Mammals could simply not compete with swift, giant predators and were forced to remain small, and most became nocturnal to evade dinosaurs which were probably active during the day. Despite that they managed to survive which allowed the further evolution of mammals into us, humans.