Answer:
1, 3 and 4
Explanation:
Did the test and saw the answers.
Answer:
a) v = 75 ft / s
, b) v = 55 ft / s
, c) Δx = 1000 ft
Explanation:
We can solve this exercise with the expressions of kinematics
a) average speed is defined as the distance traveled in a given time interval
v = (x₂-x₁) / (t₂-t₁)
v = (550 - 400) / (10 -8)
v = 75 ft / s
b) we repeat the calculations for this interval
v = (550 - 0) / (10 -0)
v = 55 ft / s
c) we clear the distance from the average velocity equation
Δx = v (t₂ -t₁)
Δx = 100 (20-10)
Δx = 1000 ft
Since toy is moving at constant speed that means that force that child is applying on toy is equal to force of friction.
Rate of speed that toy is moving is irelevant.
childs force is:
Fc = 2N
Fc = Ff (Ff -friction force)
Ff = a*Q
where Q is weight of the toy and a is friction
if we express a we get
a = F/Q = 2/8 = 0.25
Answer:
D) 117 rad/s
Explanation:
We can treat this system as a circular motion where the origin is the elbow joint, the ball rotation velocity v is 35 m/s, the rotation radius is r = 0.3m.
As the ball is leaving the pitcher hand at such speed and rotation radius. Its angular velocity is:

Answer:
Explanation:
Spring has a tendency to store energy in them and deform its shape when force is applied on it. Once the applied force is removed it regains its original shape and size.
It is in helical shape and is used in mattress to give structure and support. Spring have elastic nature and follows spring forces, F = k * x
where is the applied force, k is the spring constant and x is the amount of extension.
When a heavier person sits on a mattress, more weight is applied on springs and they form coils, as weight is removed they regains its shape again.