Answer:
1. The velocity of the car is 25 m/s
2. The mass of the bullet is 0.075 kg
3. The velocity of the boy and the bicycle is 3.11 m/s
4. The momentum of the jeepney is 40,000 kg·m/s
The momentum of the truck is is 80,000 kg·m/s
Explanation:
In our case, we are to solve the velocity, mass and momentum in four different scenarios about momentum.
For the formula, we will use:
p = mv
where
p is the momentum of an object, unit is in kg·m/s
m is the mass of the object, unit is in kg
v is the velocity of the object, unit is in m/s
For the given information
1. m = 1200 kg
p = 30,000 kg·m/s
v = ?
2. p = 1.50 kg·m/s
v = 20 m/s
m = ?
3. m1 = 30 kg
m2 = 7 kg
p = 116 kg·m/s
v = ?
4. mj = 2000 kg
mt = 4000 kg
v = 72 km/h
pj = ?, pt = ?
Solving the problem
1. For the first problem, let us use the formula for momentum to solve for the velocity of the car.
p = mv
30,000 kg.m/s=(1200kg)v30,000kg.m/s=(1200kg)v
v = \frac{30,000 kg.m/s}{1200kg}v=
1200kg
30,000kg.m/s
v = 25 m/s
2. Next, let us solve for the mass of the bullet. Again, let us use the formula for momentum then substitute the given information.
p = mv
1.50 kg·m/s = m(20 m/s)
divide both sides of the equation by 20 m/s, we have:
m = \frac{1.50kg.m/s}{20m/s}m=
20m/s
1.50kg.m/s
m = 0.075 kg
3. Next is to solve for the velocity of the boy and the bicycle.
p = (m1 + m2)v
115 kg·m/s = (30 kg + 7 kg) v
115 = 37 v
Divide both sides of the equation by 37, we have:
v = 115/37
v = 3.11 m/s
4. For the last problem, we will convert first v = 72 km/h to m/s, we have:
v = 72 km/h x 1000m/1 km x 1 hour/3600 s = 20 m/s
Now, we are ready to solve for the momentum of each object.
For the jeepney:
pj = (mj) v
pj = (2000 kg) (20 m/s)
pj = 40,000 kg·m/s
For the truck:
pt = (mt) v
pt = (4000 kg)(20 m/s)
pt = 80,000 kg·m/s
