Explanation:
Below is an attachment containing the solution.
Answer:
Sound travels through solids and liquids at the same speed
Explanation:
Because sound needs a dencer object to travel fast and since both liquid and solids are closer than gas sound travles faster in them.
Answer:
5.4 ms⁻¹
Explanation:
Here we have to use conservation of energy. Initially when the stick is held vertical, its center of mass is at some height above the ground, hence the stick has some gravitational potential energy. As the stick is allowed to fall, its rotates about one. gravitational potential energy of the stick gets converted into rotational kinetic energy.
= length of the meter stick = 1 m
= mass of the meter stick
= angular speed of the meter stick as it hits the floor
= speed of the other end of the stick
we know that, linear speed and angular speed are related as

= height of center of mass of meter stick above the floor = 
= Moment of inertia of the stick about one end
For a stick, momentof inertia about one end has the formula as

Using conservation of energy
Rotational kinetic energy of the stick = gravitational potential energy

Answer:
move at constant velocity.
Explanation:
Newton's first law (also known as law of inertia) states that:
"when the net force acting on an object is zero, the object will keep its state of rest or if it is moving, it will continue moving at constant velocity".
In the case of the probe, friction in deep space is negligible, therefore when the engine is shut down, there are no more forces acting on the probe: the net force therefore will be zero, so the probe will move at constant velocity.