Answer:
The ball took 0.4 seconds
Explanation:
» From the second newton's equation of motion.

- s is displacement, s = 80cm, s = 0.8 meters
- u is initial velocity, u = 0 [ from rest ]
- g is 10 m/s²

Answer:
Here we have some of the requirement of practical fuel are
1. It must contain large amount of stored energy. So that more amount of power output available to run the engines, motors etc.
2. It must occur in abundance in nature or be easy to produce.
3. The fuel must be made up of elements that combine easily with oxygen. Foe example if hydrogen molecules reacts with oxygen. Then the products are at the reaction of lower energy than the reactants, the result is the explosive release of energy and the product of water.
Answer:
m = 0.255kg
Explanation:
from the formular of a mass - spring system
T = 2π√m/k
making m as the subject of formular
m = T² k/4π²
T =5.91s
k = 0.288 N/m
m = 10.059/39.489
m = 0.255kg
To solve this problem, it is necessary to apply the concepts related to force described in Newton's second law, so that
F = ma
Where,
m = mass
a = Acceleration (Gravitational acceleration when there is action over the object of the earth)
Torque, as we know, is the force applied at a certain distance, that is,

Where
F= Force
d = Distance
Our values are given as,



Since the system is in equilibrium the difference of the torques is the result of the total Torque applied, that is to say






Therefore the magnitude of the frictional torque at the axle of the pulley if the system remains at rest when the balls are released is 
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