Question: A car with a mass of 800 g and velocity of 15 m/s collided with a truck moving in opposite direction with a velocity of 20 m/s, if the momentum is conserved and they both move with a common velocity of 10 m/s, what is the mass of the truck?
Answer:
0.133 kg
Explanation:
Applying the law of conservation of momentum,
Total momentum before collision = Total momentum after collision
mu+m'u' = V(m+m')................... Equation 1
Where m = mass of the car, m' = mass of the truck, u = initial velocity of the car, u' = initial velocity of the truck, V = common velocity.
From the question,
Given: m = 800 g = 0.8 kg, u = 15 m/s, u' = -20 m/s, V = 10 m/s
Substitute these values into equation 2
(0.8*15)+(m'*20) = 10(0.8+m')
Solve for m'
12-20m' = 8+10m'
-20m'-10m' = 8-12
-30m' = -4
m' = -4/-30
m' = 0.133 kg
Answer:
D. 90km/hr due West
Explanation:
Given parameters:
Displacement = 1215km
Time = 13.5hr
Unknown:
Velocity = ?
Solution:
Velocity is the displacement divided by the time taken;
Velocity = 
= 
= 90km/hr
Velocity is 90km/hr due West
Answer:
Explanation: pressure = force / area
Rearrange to get: force = pressure x area. 900 cm2 = 0.09 m2
force = 90 x 0.09
= 8.1 N
The force applied would be 1.05*9.8 = 10.3 N
the pressure is equal to F/a
area will be πr^2 = 0.002826
thus pressure will be = 10.3/0.002826= 3644.72 N/m^2
