Where??? complete your question please
Answer:
1.6 m/s
Explanation:
First you need to find the momentums of each disc by multiplying their velocities with mass.
disc 1: 7*1= 7 kg m/s
disc 2: 1*9= 9 kg m/s
Second, you need to find the total momentum of the system by adding the momentums of each sphere.
9+7= 16 kg m/s
Because momentum is conserved, this is equal to the momentum of the composite body.
Finally, to find the composite body's velocity, divide its total momentum by its mass. This is because mass*velocity=momentum
16/10=1.6
The velocity of the composite body is 1.6 m/s.
When the force on some area is doubled and the area doesn't change,
then the pressure on that area has doubled.
The answer is B friction force
As per the question Bob drops the bag full with feathers from the top of the building.
The mass of the bag(m)= 1.0 lb
Let the air resistance is neglected.As the bag is under free fall ,hence the only force that acts on the bag is the force of gravity which is in vertical downward direction.
Here the acceleration produced on bag due to the free fall will be nothing else except the acceleration due to gravity i.e g =9.8 m/s^2
Here we are asked to calculate the distance travelled by the bag at the instant 1.5 s
Hence time t= 1.5 s
From equation of kinematics we know that -
S=ut + 0.5at^2 [ here S is the distance travelled]
For motion under free fall initial velocity (u)=0.
Hence S= 0×1.5+{0.5×(-9.8)×(1.5)^2}
⇒ -S =0-11.025 m
⇒ S= 11.025 m
=11 m
Here the negative sign is taken only due to the vertical downward motion of the body .we may take is positive depending on our frame of reference .
Hence the correct option is B.
