A.) -0.40 m/s
B.) -3.60 m/s
C.) -1.80 m/s
By the law of momentum conservation:-
=>m1u1 + m2u2 = m1v1 + m2v2
=>5 x (-3.2) + 0 = 5v1 + 3.9v2
=>1.28v1 + v2 = -4.10 ---------------(i)
for elastic collision:-
=>v1 - v2 = u2 - u1
=>v1 - v2 = 0 - (-3.2)
=>v1 - v2 = 3.2 ------------------(ii)
by (i) + (ii) :-
=>2.28v1 = -0.90
=>v1 = -0.40 m/s
=>v2 = -3.60 m/s
(c) By the law of momentum conservaation:-
=>m1u1+m2u2 = (m1+m2)v
=>5 x (-3.2) + 0 = (5 + 3.9) x v
=>v = -1.80 m/s
They are made of rock and metal.
The planets closest to the Sun are called terrestrial planets because they are made of rock and metal. Plato
Answer : The approximate acceleration of the car is,
Solution : Given,
Initial velocity of the car = 0 m/s
Distance covered = 120 meter
Time taken = 6.32 second
Using second law of motion,
s = distance covered
u = initial velocity
t = time taken
a = acceleration
Now put all the given values in the above equation, we get
Therefore, the approximate acceleration of the car is,
The resultant velocity and direction of the plane with respect to the ground is 704 km/h due east.
Air velocity v₁= 720 km/h
Headwind v₂ = 16 km/h
The air velocity due to east is greater then the head wind.
So, the direction of the velocity respect to the ground will be due to east.
The velocity of plane respect to ground
The resultant velocity will be
Hence, The resultant velocity and direction of the plane with respect to the ground is 704 km/h due east.
Answer: The statements B and D are correct answers.
Work is done when the force is applied to an object then there will be displacement by the object.
In the option A, Hannah leans against her locker, but it doesn’t move. There is no displacement in this case. The work done is said to be zero in this case.
In the option B, Andy’s car rolls down a hill with the engine off. There is displacement in this case. The work is said to done in this case. At the hill, the car has a maximum potential energy.
When it rolls down then the kinetic energy of the car will increase. From the work energy theorem, the change in the kinetic energy is equal to the work done.
In the option C, A wind turbine stands still on a sunny, windless day. The work done is said to zero in this case.
In the option, A balloon expands as it is heated by the Sun. There is expansion of the balloon. The work is done in this case as the volume and the pressure will also increase on heating the balloon.
In the option E, James pedals a stationary exercise cycle that doesn’t move. No work is done in this case.
Therefore, the statements B and D are correct answers.