The law of conservation of momentum tells us that momentum
is conserved, therefore total initial momentum should be equal to total final
momentum. In this case, we can expressed this mathematically as:
mA vA + mB vB = m v
where, m is the mass in kg, v is the velocity in m/s
since m is the total mass, m = mA + mB, we can write the
equation as:
mA vA + mB vB = (mA + mB) v
furthermore, car B was at a stop signal therefore vB = 0,
hence
mA vA + 0 = (mA + mB) v
1800 (vA) = (1800 + 1500) (7.1 m/s)
<span>vA = 13.02 m/s</span>
Answer:
If you apply a force to separate 2 opposite poles, the potential energy of the system increases.
Answer:
6 V
Explanation:
We can solve the problem by using Ohm's law:
where
V is the voltage in the circuit
R is the resistance
I is the current
In this problem, we know the current, 
, and the resistance, 
, therefore we can find the voltage in the circuit:
Answer:
read this it might help some
When a moving object collides with a stationary object of identical mass, the stationary object encounters the greater collision force. When a moving object collides with a stationary object of identical mass, the stationary object encounters the greater momentum change.
Explanation:
Answer:
D
Explanation:
D) The overall work done by gravity is zero
This statement is correct .
If m be the mass of each of the children and h be the height of tower
work done by gravity on the boys in going up = - mgh
it is so because force applied by gravity = mg downwards and displacement
is upwards
work done will be negative = - mgh
Work done by gravity on boys when they come down = + mgh because both force and displacement are downwards .
Hence total work done = - mgh + mgh = 0.
The children will have same kinetic energy as the inclined surface is friction-less so no energy will be dissipated hence addition of energy to boys in both the cases will be same.
