Impermeable is a substance that is water proofed e.g glass, aluminium e.t.c <span />
False. Radio waves<span> have much longer </span>wavelengths<span> and lower frequencies </span>than<span> </span><span>visible light waves</span>
Answer:
The horizontally applied force = 2360 N
Explanation:
<em>Force:</em> Force can be defined as the product of mass and acceleration. the S.I unit of force is Newton (N)
Fh = Fr + ma......... Equation 1
Where Fh = horizontally applied force, Fr = friction force, m = mass of the crate, a = acceleration of the crate.
<em>Given: m = 400 kg, a = 1 m/s²</em>
Fr = 1/2 W, W = mg ⇒W = 400×9.8 = 3920 N
∴Fr = 1/2(3920), Fr = 1960 N
Substituting these values into equation 1
Fh = 1960 + 400×1
Fh = 1960 + 400
Fh = 2360 N
Therefore the horizontally applied force = 2360 N
Answer:
1) Time interval Blue Car Red Car
0 - 2 s Constant Velocity Increasing Velocity
2 - 3 s Constant Velocity Constant Velocity
3 - 5 s Constant Velocity Increasing Velocity
5 - 6 s Constant Velocity Decreasing Velocity
2) For Red and Blue car y₂ = 120 v = 
= 
= 20 m/s
We get the same velocity for two cars because it is the average velocity of the car at the given interval of time. It is measured for initial and final position.
3) At t = 2s, the cars are the same position, and are moving at the same rate
Position - same
Velocity - same
The position-time graph shares the same spot for two cars.
Answer: Electric current
Explanation :
The direction of the magnetic field produced by an electric current will change when the direction of the electric current changes.
For example :
If a current is flowing in a straight length of wire, the magnetic field is described by a concentric circle (using right-hand rule).
Let the field lines are in the clockwise direction and when the direction of current is reversed then the direction of the magnetic field is in anticlockwise direction.
