Answer:
the velocity is zero, the acceleration is directed downward, and the force of gravity acting on the ball is directed downward
Explanation:
Is this exercise in kinematics
v = v₀ - g t
where g is the acceleration of the ball, which is created by the attraction of the ball to the Earth.
At the highest point
velocity must be zero.
The acceleration depends on the Earth therefore it is constant at this point and with a downward direction.
The force of the earth on the ball is towards the center of the Earth, that is, down
all other alternatives are wrong
An iron pot is mostly magnetic
Answer:
1 kg
Explanation:
Applying,
Hook's law,
F = ke................. Equation 1
Where F = force, k = force constant of the spring, e = extension.
But from the question,
The weight of the bottle is the force acting on the spring scale
therefore,
mg = ke............ Equation 2
Where m = mass of the bottle, g = acceleration due to gravity.
make k the subject of the equation
k = mg/e............ Equation 3
Given: m = 0.5 kg, e = 1 cm = 0.01 m
Constant: g = 9.8 m/s²
k = (0.5×9.8)/0.01
k = 490 N/m
If the mass of the second bottle is weighed,
given: e = 2 cm = 0.02 m
subtitute into equation 1
m×9.8 = 490×0.02
9.8m = 9.8
m = 9.8/9.8
m = 1 kg.
Hence the mass of the second bottle is 1 kg
Answer: (c) 2000 N
Explanation:
Given Data :
▪ Initial velocity = zero ( body is at rest)
▪ Distance travelled = 100m
▪ Final kinetic energy = 200000J
To Find :
▪ Resultant force acting on the car.
Therefore:
W = F × d = ΔK ----------------- eq 1.
where,
W = work done
F = applied force
d = distance
ΔK = change in kinetic energy
Calculation :
→ F × d = Kf - Ki ----------------- eq 2.
Where:
Kf = Final kinetic energy = 200000
Ki = initial kinetic energy = 0
Substituting our values into the formula from equation (2)
→ F × 100 = 200000 - 0
→ F = 200000/100
→ F = 2000N
