First speed = 20km/h
Time = 3 hours
Distance = 3×20
<h3> = <u>60 km</u></h3>
Second speed = 30km/h
Time = 4 hours
Distance = 4×30
<h3> = <u>120 km</u></h3>
Total distance = 60+120 = <u>180km</u>
Total time = 3+4 =<u> 7 hours</u>
Average speed = 180/7
<h3> = <u>25.71</u><u> </u><u>km</u><u>/</u><u>h</u></h3>
Hope this will help...
Answer:

Explanation:
<u>Conservation of Momentum
</u>
The total momentum of a system of two particles is

Where m1,m2,v1, and v2 are the respective masses and velocities of the particles at a given time. Then, the two particles collide and change their velocities to v1' and v2'. The final momentum is now

The momentum is conserved if no external forces are acting on the system, thus

Let's put some numbers in the problem and say



120=120
It means that when the particles collide, the first mass returns at 6 m/s and the second continues in the same direction at 28 m/s
Answer:
The answer to your question is:
Explanation:
Data
mass = 4.33 kg
E = 41.7 J
v = ?
Formula
Ke = (1/2)mv²
Clear v from the equation
v = √2ke/m
Substitution
v = √2(41.7)/4.33
v = 19.26 m/s Result
Answer:
True
Explanation:
Matter can be in the form of a particle or a wave. This is known as the dual nature of matter. This concept was proposed by Louis de Broglie and was named after him. This phenomenon has been observed for all the elementary particles.
The de Broglie wavelength is given by

Where
h = Planck's constant
p = Particles momentum
m = Mass of particle
v = Velocity of particle
Answer:
<h2>0.67 m/s²</h2>
Explanation:
The acceleration of an object given it's mass and the force acting on it can be found by using the formula

f is the force
m is the mass
From the question we have

We have the final answer as
<h3>0.67 m/s²</h3>
Hope this helps you