Ok so we are given the radius of 7cm and time of 5 seconds.
From the data we got we can calculate speed, frequency, perimeter and area of the semicircle.
Let's start with perimeter.
We know that perimeter of circle is
so the perimeter of semicircle is
or simply 
So the perimeter is equal to:

So this is the length of a curve or let's say the distance.
Now let's look at the linear speed
where d is distance and t time.
We know the distance and we know the time.
So let's calculate it.

Hope this helps.
r3t40
Given : Initial velocity = -1.3 m/s
Final Velocity = -6.5 m/s.
Time = 25 minutes.
To find : Average acceleration.
Solution: We are given units in meter/second (m/s).
So, we need to convert time 25 minutes in seconds.
1 minute = 60 seconds.
25 minutes = 60*25 = 1500 seconds.
Formula for average acceleration is given by,

We are not given intial time, so we can take initial time =0.
Plugging values in the above formula.

= 
= -0.003467
or
.
Explanation :
The interaction between two objects is termed as the collision. The collision can be of two types i.e. elastic collision and inelastic collision.
In this case, two identical carts travel at the same speed toward each other, and then a collision occurs. In an inelastic collision, the momentum before and after the collision remains the same but its kinetic energy gets lost.
After the collision, both the object sticks over each other and moves with one velocity.
Out of the given graph, the graph that shows a perfectly inelastic collision is attached. It shows that after the collision both the carts move with the same velocity.
let the length of the beam be "L"
from the diagram
AD = length of beam = L
AC = CD = AD/2 = L/2
BC = AC - AB = (L/2) - 1.10
BD = AD - AB = L - 1.10
m = mass of beam = 20 kg
m₁ = mass of child on left end = 30 kg
m₂ = mass of child on right end = 40 kg
using equilibrium of torque about B
(m₁ g) (AB) = (mg) (BC) + (m₂ g) (BD)
30 (1.10) = (20) ((L/2) - 1.10) + (40) (L - 1.10)
L = 1.98 m
Answer:
4.9 cm
Explanation:
From Hook's Law,
F = ke......................... Equation 1
Where F= force, e = extension, k = spring constant.
Note: the Force acting on the the spring is the weight of the mass.
W = mg.
F = mg.................... Equation 2
Where m = mass, g = acceleration due to gravity
Substitute equation 2 into equation 1
mg = ke
make e the subject of the equation
e = mg/k............... Equation 3.
Given: m = 2 kg, g = 9.8 m/s², k = 400 N/m
e = (2×9.8)/400
e = 19.6/400
e = 0.049 m
e = 4.9 cm