Answer : Option C) copy the movements performed during the activity.
Explanation : Arm circles are an effective dynamic stretch for swimmers because they copy the movements performed during the activity.
During swimming when the arm circles are performed it stretches the triceps brachii, loosens the shoulder blade and stretches the side muscles.
Often many people are observed to perform this arm circles stretch without bringing the elbow behind the head, but especially for swimmers, this increases the stretching length and reduces stress while swimming.
Answer:
32500N
Explanation:
Data obtained from the question include:
m (mass) = 2500 kg
a (acceleration) = 13 m/s2
F (force) =?
Force is the product of mass and acceleration. It is represented mathematically as:
Force = mass x acceleration
F = m x a
With the above formula, the force with which the car strikes the barrier can be obtained as follow:
F = m x a
F = 2500 x 13
F = 32500N
Therefore, the car will strike the barrier with a force of 32500N
Student 2 has the greatest average speed
Answer:
True
Explanation:
- A conservative force is a force whose work done does not depend on the path taken, but only on the final and starting point.
- The mechanical energy of an object is defined as the sum of the kinetic energy (K) and the potential energy (U): E = K + U
- The law of conservation of energy states that, in case only conservative forces are acting on the object, the mechanical energy of the object E is conserved
- In case non-conservative forces are acting on the object, the mechanical energy is no longer constant. An example of non-conservative force is the force of friction: when the force of friction is acting on a car in motion, the car is slowed down by the effect of the force, losing some of its kinetic energy, K. If the car is travelling on a flat road, then its potential energy U does not change: this means that the mechanical energy of the car, E, is decreasing, so it is no longer conserved.
Answer:
d= 852.01 m
Explanation:
Given that
Speed of sound in air u= 343 m/s
Speed of sound in concrete v= 3000 m/s
Lets take time taken by sound in the concrete is t then the time taken by sound in air will be t+2.2 s .
The distance (d)travel will be same in both the cases.
We know that
Distance = Velocity x time
So
d= 3000 x t = 343 x (t+2.2)
3000 t = 343 t + 343 x 2.2
t= 0.284 s
So the distance d
d= 3000 x 0.284 m
d= 852.01 m