Answer:
at the highest point of the path the acceleration of ball is same as acceleration due to gravity
Explanation:
At the highest point of the path of the ball the speed of the ball becomes zero as the acceleration due to gravity will decelerate the motion of ball due to which the speed of ball will keep on decreasing and finally it comes to rest
So here we will say that at the highest point of the path the speed of the ball comes to zero
now by the force diagram we can say that net force on the ball due to gravity is given by

now the acceleration of ball is given as


so at the highest point of the path the acceleration of ball is same as acceleration due to gravity
More force needs to be applied
Answer:
a) Yes, there are
shakes in a second (
) in a year there are 31,536,000 seconds... that is 3.1536x
(
)
b) Note that the defined universe day will have 60*60*24=86400 universe seconds if the seconds are defined as normal seconds.
Also one universe day (or 86400 universe seconds) is equivalent to 1010 years. Now using a rule of three we can know the seconds that humans have existed.

That is about 2 and half hours.
Answer:
25°C
Explanation:
Using the linear expansivity formula expressed as;
∝ = ΔL/lΔθ
∝ is coefficient of lineat expansion = 1.2 ∙ 10⁻⁵ °C⁻¹
ΔL is the change in length = 6.00036-6
ΔL = 0.00036m
l is the original length = 6m
Δθ is the change in temperature =θ₂-20
Substituting into the formula;
1.2 ∙ 10⁻⁵ °C⁻¹ = 0.00036/6(θ₂-20)
cross multiply
1.2 ∙ 10⁻⁵ * 6 = 0.00036/(θ₂-20)
7.2 ∙ 10⁻⁵= 0.00036/(θ₂-20)
0.00036 = 7.2 ∙ 10⁻⁵(θ₂-20)
0.00036 = 7.2 ∙ 10⁻⁵θ₂-144∙ 10⁻⁵
7.2 ∙ 10⁻⁵θ₂ = 0.00036+0.00144
7.2 ∙ 10⁻⁵θ₂ = 0.0018
θ₂ = 0.0018/0.000072
θ₂ = 25°C
Hence the temperature at which this bar must be acidic for its compression is 6,00036 m is 25°C
Answer:
C. 39 m/s
Explanation:
First we need to calculate the total force required to move the train along the inclined plane. So, it is clear that the work done will be equal to the component of the weight that is parallel to the inclined plane, because there is no frictional force present:
Force = F = mg Sin θ
where,
m = mass of train = 3.3 x 10⁶ kg
g = 9.8 m/s²
θ = Angle of Inclination = 0.64°
Therefore,
F = (3.3 x 10⁶ kg)(9.8 m/s²)Sin 0.64°
F = 3.612 x 10⁵ N
Now, the formula for power is:
P = FV
V = P/F
where,
V = Velocity of Train = ?
P = Power of Engine = 14 MW = 1.4 x 10⁷ W
Therefore,
V = 1.4 x 10⁷ W/3.612 x 10⁵ N
V = 38.75 m/s
which is approximately equal to:
<u>C. 39 m/s</u>