The estimate of how many stars are in a galaxy is 100 thousand million
Answer:
Angle of reflection is also 65 degrees
Explanation:
angle of incidence = angle of reflection
Answer:
The net friction force is 8.01 N
Explanation:
Net friction force = mass of hockey puck × acceleration
From the equations of motion
v^2 = u^2 + 2as
v = 40 m/s
u = 0 m/s (puck was initially at rest)
s = 30 m
40^2 = 0^2 + 2×a×30
60a = 1600
a = 1600/60 = 26.7 m/s^2
The acceleration of the puck is 26.7 m/s^2
Net friction force = 0.3 × 26.7 = 8.01 N
Answer:
The acceleration at lowest point is 19.62 m/s^2
Explanation:
Conservation of energy is an concept in which it is stated that the energy of an isolated object remains the same. Energy changes from one form to another.
Lets Assume
Constant of string is K
By using the conservation of energy we will have the following equation
1/2 x 80^2 x K = m x 9.81 x 120
3200 K = 1177.2 m
K = 1177.2 m / 3200
K = 0.368 m
At the lowest point we will have
a = ( K x X - m x g ) / m
a = ( 0.368 m x 80 - m x 9.81 ) / m
a = 19.62 m / s^2
So, the acceleration at lowest point is 19.62 m/s^2
Answer: acceleration a = 25m/s^2
Explanation:
Given that:
The plane travels with constant acceleration
x1 = 241.22 m at t1 = 3.70 s
x2 = 297.60 m at t2 = 4.20 s
x3 = 360.23 m at t3 = 4.70 s.
We need to calculate the velocity in the two time intervals.
Interval 1:
Average Velocity v1 = ∆x/∆t = (x2 - x1)/(t2-t1)
v1 = (297.60-241.22)/(4.20-3.70) = 112.76m/s
Interval 2:
Average Velocity v2 = ∆x/∆t = (x3-x2)/(t3-t2)
v2 = (360.23-297.60)/(4.70-4.20)
v2 = 125.26m/s
Acceleration:
Acceleration a = ∆v/∆t
∆v = v2-v1 = 125.26m/s-112.76m/s = 12.5m/s
∆t = change in average time of the two intervals = (t3-t1)/2 = (4.70-3.70)/2 = 0.5s
a = 12.5/0.5 = 25m/s^2
