Answer:
24.084 m/s
Explanation:
From the law of conservation of linear momentum
Total momentum before collision equals to the total momentum after collision
Since momentum=mv where m is mass and v is velocity
where
is the mass of the truck,
is velocity of the truck,
is the common velocity of moving and standing truck after collision and
is the mass of the standing truck
Making
the subject we obtain
Substituting
as 25000 Kg,
as 22.3 m/s,
as 2000 Kg we obtain
Therefore, assuming no friction and considering that after collision they still move eastwards hence common velocity and initial truck velocities are positive
The truck was moving at 24.084 m/s
Answer:
Frequency, f = 1 unit
Explanation:
It is given that,
Period of the wave, T = 1 unit
We need to find the frequency of the wave. There exist an inverse relationship between period and the frequency of the wave. It is given by :

Or


f = 1 unit
So, the frequency of the wave is 1 unit. Hence, this is the required solution.
Answer:
4.62 s
Explanation:
We are given that
Initial angular speed,



Substitute the values






Hence, the wheel takes 4.62 s to come to rest.
Answer:

Explanation:
The magnitude of the electrostatic force between two charged objects is

where
k is the Coulomb's constant
q1 and q2 are the two charges
r is the separation between the two charges
The force is attractive if the charges have opposite sign and repulsive if the charges have same sign.
In this problem, we have:
is the distance between the charges
since the charges are identical
is the force between the charges
Re-arranging the equation and solving for q, we find the charge on each drop:

Answer:
The coefficient of static friction between the box and floor is, μ = 0.061
Explanation:
Given data,
The mass of the box, m = 50 kg
The force exerted by the person, F = 50 N
The time period of motion, t = 10 s
The frictional force acting on the box, f = 30 N
The normal force on the box, η = mg
= 50 x 9.8
= 490 N
The coefficient of friction,
μ = f/ η
= 30 / 490
= 0.061
Hence, the coefficient of static friction between the box and floor is, μ = 0.061