Answer:
air water iron helium
v(m/s) 280 2200 17780 39682
Explanation:
The speed of a wave depends on the physical properties of the medium where it travels, in the case of a longitudinal wave such as sound, it depends on the resistance to deformation (volume modulus and the density of the medium
v = 
in the mentioned materials they are constant
air water iron helium
B 1 10⁵ 2.2 10⁹ 140 10⁹ 0.05 10⁹
ρ 1.28 997 7874 1.26
v(m/s) 280 2200 17780 39682
One part of a freely swinging magnet always points to the Earth's magnetic pole in the Northern Hemisphere.
2HCl + MgO ---> MgCl2 + H2O
The contact force is indeed caused by "Contact".
Air resistance is basically a type of friction, which is apparently present providing two object contact.
The rest selections are all interaction force, which is not necessarily caused by contact.
Answer:
Part a)

Part b)

Part c)

Explanation:
As we know that acceleration is rate of change in velocity of the object
So here we know that


Part a)
differentiate x and y two times with respect to time to find the acceleration






Now the acceleration of the object is given as

at t= 1.1 s we have

now the net force of the object is given as



now magnitude of the force will be

Part b)
Direction of the force is given as



Part c)
For velocity of the particle we have




now at t = 1.1 s

now the direction of the velocity is given as


